Snap for 10447354 from ea16fc1b4d5915b6c027c4feefb522e3fd0c94a7 to mainline-wifi-releaseaml_wif_341711020aml_wif_341610000aml_wif_341510000aml_wif_341410080aml_wif_341310010aml_wif_341110010aml_wif_341011010aml_wif_340913010android14-mainline-wifi-release

Change-Id: I01b69c4ddb201985da452718d406f0aef3e5dca2

41 files changed, 2661 insertions, 108 deletions

diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index 43f6c71..1bae39b 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,5 +1,6 @@
 {
   "git": {
-    "sha1": "d2f9cda3a00a62ae1e0eeeea8f0a081c7598b8c5"
-  }
-}
+    "sha1": "76a8274f948fbe3551413dc09026b733aca71995"
+  },
+  "path_in_vcs": ""
+}
\ No newline at end of file
diff --git a/0.3.3/Android.bp b/0.3.3/Android.bp
new file mode 100644
index 0000000..65601b5
--- /dev/null
+++ b/0.3.3/Android.bp
@@ -0,0 +1,69 @@
+// This file is generated by cargo2android.py --config cargo2android.json.
+// Do not modify this file as changes will be overridden on upgrade.
+
+package {
+    default_applicable_licenses: ["external_rust_crates_heck_license_0_3_3"],
+}
+
+// Added automatically by a large-scale-change that took the approach of
+// 'apply every license found to every target'. While this makes sure we respect
+// every license restriction, it may not be entirely correct.
+//
+// e.g. GPL in an MIT project might only apply to the contrib/ directory.
+//
+// Please consider splitting the single license below into multiple licenses,
+// taking care not to lose any license_kind information, and overriding the
+// default license using the 'licenses: [...]' property on targets as needed.
+//
+// For unused files, consider creating a 'fileGroup' with "//visibility:private"
+// to attach the license to, and including a comment whether the files may be
+// used in the current project.
+//
+// large-scale-change included anything that looked like it might be a license
+// text as a license_text. e.g. LICENSE, NOTICE, COPYING etc.
+//
+// Please consider removing redundant or irrelevant files from 'license_text:'.
+// See: http://go/android-license-faq
+license {
+    name: "external_rust_crates_heck_license_0_3_3",
+    visibility: [":__subpackages__"],
+    license_kinds: [
+        "SPDX-license-identifier-Apache-2.0",
+        "SPDX-license-identifier-MIT",
+    ],
+    license_text: [
+        "LICENSE-APACHE",
+        "LICENSE-MIT",
+    ],
+}
+
+rust_test {
+    name: "heck_test_src_lib_deprecated",
+    host_supported: true,
+    crate_name: "heck",
+    cargo_env_compat: true,
+    cargo_pkg_version: "0.3.3",
+    srcs: ["src/lib.rs"],
+    test_suites: ["general-tests"],
+    auto_gen_config: true,
+    test_options: {
+        unit_test: true,
+    },
+    edition: "2018",
+    rustlibs: [
+        "libunicode_segmentation",
+    ],
+}
+
+rust_library {
+    name: "libheck_deprecated",
+    host_supported: true,
+    crate_name: "heck",
+    cargo_env_compat: true,
+    cargo_pkg_version: "0.3.3",
+    srcs: ["src/lib.rs"],
+    edition: "2018",
+    rustlibs: [
+        "libunicode_segmentation",
+    ],
+}
diff --git a/0.3.3/Cargo.toml b/0.3.3/Cargo.toml
new file mode 100644
index 0000000..fc9c28d
--- /dev/null
+++ b/0.3.3/Cargo.toml
@@ -0,0 +1,27 @@
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies
+#
+# If you believe there's an error in this file please file an
+# issue against the rust-lang/cargo repository. If you're
+# editing this file be aware that the upstream Cargo.toml
+# will likely look very different (and much more reasonable)
+
+[package]
+edition = "2018"
+name = "heck"
+version = "0.3.3"
+authors = ["Without Boats <woboats@gmail.com>"]
+include = ["src/**/*", "LICENSE-*", "README.md", "CHANGELOG.md"]
+description = "heck is a case conversion library."
+homepage = "https://github.com/withoutboats/heck"
+documentation = "https://docs.rs/heck"
+readme = "README.md"
+keywords = ["string", "case", "camel", "snake", "unicode"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/withoutboats/heck"
+[dependencies.unicode-segmentation]
+version = "1.2.0"
diff --git a/0.3.3/Cargo.toml.orig b/0.3.3/Cargo.toml.orig
new file mode 100644
index 0000000..80acd39
--- /dev/null
+++ b/0.3.3/Cargo.toml.orig
@@ -0,0 +1,16 @@
+[package]
+authors = ["Without Boats <woboats@gmail.com>"]
+name = "heck"
+version = "0.3.3"
+edition = "2018"
+license = "MIT OR Apache-2.0"
+description = "heck is a case conversion library."
+homepage = "https://github.com/withoutboats/heck"
+repository = "https://github.com/withoutboats/heck"
+documentation = "https://docs.rs/heck"
+keywords = ["string", "case", "camel", "snake", "unicode"]
+readme = "README.md"
+include = ["src/**/*", "LICENSE-*", "README.md", "CHANGELOG.md"]
+
+[dependencies]
+unicode-segmentation = "1.2.0"
diff --git a/0.3.3/LICENSE b/0.3.3/LICENSE
new file mode 120000
index 0000000..6b579aa
--- /dev/null
+++ b/0.3.3/LICENSE
@@ -0,0 +1 @@
+LICENSE-APACHE
\ No newline at end of file
diff --git a/0.3.3/LICENSE-APACHE b/0.3.3/LICENSE-APACHE
new file mode 100644
index 0000000..16fe87b
--- /dev/null
+++ b/0.3.3/LICENSE-APACHE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
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+   "License" shall mean the terms and conditions for use, reproduction,
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+   "You" (or "Your") shall mean an individual or Legal Entity
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+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
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+   "Contribution" shall mean any work of authorship, including
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+   communication on electronic mailing lists, source code control systems,
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+   Licensor for the purpose of discussing and improving the Work, but
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+   designated in writing by the copyright owner as "Not a Contribution."
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+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
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+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
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+3. Grant of Patent License. Subject to the terms and conditions of
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+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
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+   where such license applies only to those patent claims licensable
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+   cross-claim or counterclaim in a lawsuit) alleging that the Work
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+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
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+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
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+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
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+   (d) If the Work includes a "NOTICE" text file as part of its
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+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
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+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
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+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
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+Copyright [yyyy] [name of copyright owner]
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+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+	http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/0.3.3/LICENSE-MIT b/0.3.3/LICENSE-MIT
new file mode 100644
index 0000000..e69282e
--- /dev/null
+++ b/0.3.3/LICENSE-MIT
@@ -0,0 +1,25 @@
+Copyright (c) 2015 The Rust Project Developers
+
+Permission is hereby granted, free of charge, to any
+person obtaining a copy of this software and associated
+documentation files (the "Software"), to deal in the
+Software without restriction, including without
+limitation the rights to use, copy, modify, merge,
+publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software
+is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice
+shall be included in all copies or substantial portions
+of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
+ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
+TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
+PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
+IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
diff --git a/0.3.3/METADATA b/0.3.3/METADATA
new file mode 100644
index 0000000..dd9970c
--- /dev/null
+++ b/0.3.3/METADATA
@@ -0,0 +1,19 @@
+name: "heck"
+description: "heck is a case conversion library."
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://crates.io/crates/heck"
+  }
+  url {
+    type: ARCHIVE
+    value: "https://static.crates.io/crates/heck/heck-0.3.3.crate"
+  }
+  version: "0.3.3"
+  license_type: NOTICE
+  last_upgrade_date {
+    year: 2021
+    month: 6
+    day: 21
+  }
+}
diff --git a/0.3.3/MODULE_LICENSE_APACHE2 b/0.3.3/MODULE_LICENSE_APACHE2
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/0.3.3/MODULE_LICENSE_APACHE2
diff --git a/0.3.3/NOTICE b/0.3.3/NOTICE
new file mode 120000
index 0000000..7a694c9
--- /dev/null
+++ b/0.3.3/NOTICE
@@ -0,0 +1 @@
+LICENSE
\ No newline at end of file
diff --git a/0.3.3/OWNERS b/0.3.3/OWNERS
new file mode 100644
index 0000000..46fc303
--- /dev/null
+++ b/0.3.3/OWNERS
@@ -0,0 +1 @@
+include platform/prebuilts/rust:/OWNERS
diff --git a/0.3.3/README.md b/0.3.3/README.md
new file mode 100644
index 0000000..33f2a5d
--- /dev/null
+++ b/0.3.3/README.md
@@ -0,0 +1,63 @@
+# **heck** is a case conversion library
+
+!["I specifically requested the opposite of this."](./no_step_on_snek.png)
+
+This library exists to provide case conversion between common cases like
+CamelCase and snake_case. It is intended to be unicode aware, internally
+consistent, and reasonably well performing.
+
+## Definition of a word boundary
+
+Word boundaries are defined as the "unicode words" defined in the
+`unicode_segmentation` library, as well as within those words in this manner:
+
+1. All underscore characters are considered word boundaries.
+2. If an uppercase character is followed by lowercase letters, a word boundary
+is considered to be just prior to that uppercase character.
+3. If multiple uppercase characters are consecutive, they are considered to be
+within a single word, except that the last will be part of the next word if it
+is followed by lowercase characters (see rule 2).
+
+That is, "HelloWorld" is segmented `Hello|World` whereas "XMLHttpRequest" is
+segmented `XML|Http|Request`.
+
+Characters not within words (such as spaces, punctuations, and underscores)
+are not included in the output string except as they are a part of the case
+being converted to. Multiple adjacent word boundaries (such as a series of
+underscores) are folded into one. ("hello__world" in snake case is therefore
+"hello_world", not the exact same string). Leading or trailing word boundary
+indicators are dropped, except insofar as CamelCase capitalizes the first word.
+
+## Cases contained in this library:
+
+1. CamelCase
+2. snake_case
+3. kebab-case
+4. SHOUTY_SNAKE_CASE
+5. mixedCase
+6. Title Case
+7. SHOUTY-KEBAB-CASE
+
+## Contributing
+
+PRs of additional well-established cases welcome.
+
+This library is a little bit opinionated (dropping punctuation, for example).
+If that doesn't fit your use case, I hope there is another crate that does. I
+would prefer **not** to receive PRs to make this behavior more configurable.
+
+Bug reports & fixes always welcome. :-)
+
+## MSRV
+
+The minimum supported Rust version for this crate is 1.32.0. This may change in
+minor or patch releases, but we probably won't ever require a very recent
+version. If you would like to have a stronger guarantee than that, please open
+an issue.
+
+## License
+
+heck is distributed under the terms of both the MIT license and the
+Apache License (Version 2.0).
+
+See LICENSE-APACHE and LICENSE-MIT for details.
diff --git a/0.3.3/TEST_MAPPING b/0.3.3/TEST_MAPPING
new file mode 100644
index 0000000..e5f5c4c
--- /dev/null
+++ b/0.3.3/TEST_MAPPING
@@ -0,0 +1,27 @@
+// Generated by update_crate_tests.py for tests that depend on this crate.
+{
+  "imports": [
+    {
+      "path": "external/rust/crates/argh"
+    },
+    {
+      "path": "external/rust/crates/base64"
+    }
+  ],
+  "presubmit": [
+    {
+      "name": "authfs_device_test_src_lib"
+    },
+    {
+      "name": "heck_test_src_lib"
+    }
+  ],
+  "presubmit-rust": [
+    {
+      "name": "authfs_device_test_src_lib"
+    },
+    {
+      "name": "heck_test_src_lib"
+    }
+  ]
+}
diff --git a/0.3.3/cargo2android.json b/0.3.3/cargo2android.json
new file mode 100644
index 0000000..d36fb44
--- /dev/null
+++ b/0.3.3/cargo2android.json
@@ -0,0 +1,5 @@
+{
+  "device": true,
+  "run": true,
+  "tests": true
+}
\ No newline at end of file
diff --git a/src/camel.rs b/0.3.3/src/camel.rs
index 6949435..6949435 100644
--- a/src/camel.rs
+++ b/0.3.3/src/camel.rs
diff --git a/0.3.3/src/kebab.rs b/0.3.3/src/kebab.rs
new file mode 100644
index 0000000..75e5978
--- /dev/null
+++ b/0.3.3/src/kebab.rs
@@ -0,0 +1,49 @@
+use crate::{lowercase, transform};
+
+/// This trait defines a kebab case conversion.
+///
+/// In kebab-case, word boundaries are indicated by hyphens.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::KebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(sentence.to_kebab_case(), "we-are-going-to-inherit-the-earth");
+/// ```
+pub trait KebabCase: ToOwned {
+    /// Convert this type to kebab case.
+    fn to_kebab_case(&self) -> Self::Owned;
+}
+
+impl KebabCase for str {
+    fn to_kebab_case(&self) -> Self::Owned {
+        transform(self, lowercase, |s| s.push('-'))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::KebabCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_kebab_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "camel-case");
+    t!(test2: "This is Human case." => "this-is-human-case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed-up-camel-case-with-some-spaces");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed-up-snake-case-with-some-spaces");
+    t!(test5: "kebab-case" => "kebab-case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "shouty-snake-case");
+    t!(test7: "snake_case" => "snake-case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this-contains-all-kinds-of-word-boundaries");
+    t!(test9: "XΣXΣ baffle" => "xσxς-baffle");
+    t!(test10: "XMLHttpRequest" => "xml-http-request");
+}
diff --git a/0.3.3/src/lib.rs b/0.3.3/src/lib.rs
new file mode 100644
index 0000000..00a9fbe
--- /dev/null
+++ b/0.3.3/src/lib.rs
@@ -0,0 +1,181 @@
+//! **heck** is a case conversion library.
+//!
+//! This library exists to provide case conversion between common cases like
+//! CamelCase and snake_case. It is intended to be unicode aware, internally,
+//! consistent, and reasonably well performing.
+//!
+//! ## Definition of a word boundary
+//!
+//! Word boundaries are defined as the "unicode words" defined in the
+//! `unicode_segmentation` library, as well as within those words in this
+//! manner:
+//!
+//! 1. All underscore characters are considered word boundaries.
+//! 2. If an uppercase character is followed by lowercase letters, a word
+//! boundary is considered to be just prior to that uppercase character.
+//! 3. If multiple uppercase characters are consecutive, they are considered to
+//! be within a single word, except that the last will be part of the next word
+//! if it is followed by lowercase characters (see rule 2).
+//!
+//! That is, "HelloWorld" is segmented `Hello|World` whereas "XMLHttpRequest" is
+//! segmented `XML|Http|Request`.
+//!
+//! Characters not within words (such as spaces, punctuations, and underscores)
+//! are not included in the output string except as they are a part of the case
+//! being converted to. Multiple adjacent word boundaries (such as a series of
+//! underscores) are folded into one. ("hello__world" in snake case is therefore
+//! "hello_world", not the exact same string). Leading or trailing word boundary
+//! indicators are dropped, except insofar as CamelCase capitalizes the first
+//! word.
+//!
+//! ### Cases contained in this library:
+//!
+//! 1. CamelCase
+//! 2. snake_case
+//! 3. kebab-case
+//! 4. SHOUTY_SNAKE_CASE
+//! 5. mixedCase
+//! 6. Title Case
+//! 7. SHOUTY-KEBAB-CASE
+#![deny(missing_docs)]
+
+mod camel;
+mod kebab;
+mod mixed;
+mod shouty_kebab;
+mod shouty_snake;
+mod snake;
+mod title;
+
+pub use camel::CamelCase;
+pub use kebab::KebabCase;
+pub use mixed::MixedCase;
+pub use shouty_kebab::ShoutyKebabCase;
+pub use shouty_snake::{ShoutySnakeCase, ShoutySnekCase};
+pub use snake::{SnakeCase, SnekCase};
+pub use title::TitleCase;
+
+use unicode_segmentation::UnicodeSegmentation;
+
+fn transform<F, G>(s: &str, with_word: F, boundary: G) -> String
+where
+    F: Fn(&str, &mut String),
+    G: Fn(&mut String),
+{
+    /// Tracks the current 'mode' of the transformation algorithm as it scans
+    /// the input string.
+    ///
+    /// The mode is a tri-state which tracks the case of the last cased
+    /// character of the current word. If there is no cased character
+    /// (either lowercase or uppercase) since the previous word boundary,
+    /// than the mode is `Boundary`. If the last cased character is lowercase,
+    /// then the mode is `Lowercase`. Othertherwise, the mode is
+    /// `Uppercase`.
+    #[derive(Clone, Copy, PartialEq)]
+    enum WordMode {
+        /// There have been no lowercase or uppercase characters in the current
+        /// word.
+        Boundary,
+        /// The previous cased character in the current word is lowercase.
+        Lowercase,
+        /// The previous cased character in the current word is uppercase.
+        Uppercase,
+    }
+
+    let mut out = String::new();
+    let mut first_word = true;
+
+    for word in s.unicode_words() {
+        let mut char_indices = word.char_indices().peekable();
+        let mut init = 0;
+        let mut mode = WordMode::Boundary;
+
+        while let Some((i, c)) = char_indices.next() {
+            // Skip underscore characters
+            if c == '_' {
+                if init == i {
+                    init += 1;
+                }
+                continue;
+            }
+
+            if let Some(&(next_i, next)) = char_indices.peek() {
+                // The mode including the current character, assuming the
+                // current character does not result in a word boundary.
+                let next_mode = if c.is_lowercase() {
+                    WordMode::Lowercase
+                } else if c.is_uppercase() {
+                    WordMode::Uppercase
+                } else {
+                    mode
+                };
+
+                // Word boundary after if next is underscore or current is
+                // not uppercase and next is uppercase
+                if next == '_' || (next_mode == WordMode::Lowercase && next.is_uppercase()) {
+                    if !first_word {
+                        boundary(&mut out);
+                    }
+                    with_word(&word[init..next_i], &mut out);
+                    first_word = false;
+                    init = next_i;
+                    mode = WordMode::Boundary;
+
+                // Otherwise if current and previous are uppercase and next
+                // is lowercase, word boundary before
+                } else if mode == WordMode::Uppercase && c.is_uppercase() && next.is_lowercase() {
+                    if !first_word {
+                        boundary(&mut out);
+                    } else {
+                        first_word = false;
+                    }
+                    with_word(&word[init..i], &mut out);
+                    init = i;
+                    mode = WordMode::Boundary;
+
+                // Otherwise no word boundary, just update the mode
+                } else {
+                    mode = next_mode;
+                }
+            } else {
+                // Collect trailing characters as a word
+                if !first_word {
+                    boundary(&mut out);
+                } else {
+                    first_word = false;
+                }
+                with_word(&word[init..], &mut out);
+                break;
+            }
+        }
+    }
+
+    out
+}
+
+fn lowercase(s: &str, out: &mut String) {
+    let mut chars = s.chars().peekable();
+    while let Some(c) = chars.next() {
+        if c == 'Σ' && chars.peek().is_none() {
+            out.push('ς');
+        } else {
+            out.extend(c.to_lowercase());
+        }
+    }
+}
+
+fn uppercase(s: &str, out: &mut String) {
+    for c in s.chars() {
+        out.extend(c.to_uppercase())
+    }
+}
+
+fn capitalize(s: &str, out: &mut String) {
+    let mut char_indices = s.char_indices();
+    if let Some((_, c)) = char_indices.next() {
+        out.extend(c.to_uppercase());
+        if let Some((i, _)) = char_indices.next() {
+            lowercase(&s[i..], out);
+        }
+    }
+}
diff --git a/src/mixed.rs b/0.3.3/src/mixed.rs
index 71089f2..71089f2 100644
--- a/src/mixed.rs
+++ b/0.3.3/src/mixed.rs
diff --git a/0.3.3/src/shouty_kebab.rs b/0.3.3/src/shouty_kebab.rs
new file mode 100644
index 0000000..0225471
--- /dev/null
+++ b/0.3.3/src/shouty_kebab.rs
@@ -0,0 +1,51 @@
+use crate::{transform, uppercase};
+
+/// This trait defines a shouty kebab case conversion.
+///
+/// In SHOUTY-KEBAB-CASE, word boundaries are indicated by hyphens and all
+/// words are in uppercase.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ShoutyKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(sentence.to_shouty_kebab_case(), "WE-ARE-GOING-TO-INHERIT-THE-EARTH");
+/// ```
+pub trait ShoutyKebabCase: ToOwned {
+    /// Convert this type to shouty kebab case.
+    fn to_shouty_kebab_case(&self) -> Self::Owned;
+}
+
+impl ShoutyKebabCase for str {
+    fn to_shouty_kebab_case(&self) -> Self::Owned {
+        transform(self, uppercase, |s| s.push('-'))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ShoutyKebabCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_shouty_kebab_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "CAMEL-CASE");
+    t!(test2: "This is Human case." => "THIS-IS-HUMAN-CASE");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED-UP-CAMEL-CASE-WITH-SOME-SPACES");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "MIXED-UP-SNAKE-CASE-WITH-SOME-SPACES");
+    t!(test5: "kebab-case" => "KEBAB-CASE");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY-SNAKE-CASE");
+    t!(test7: "snake_case" => "SNAKE-CASE");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS-CONTAINS-ALL-KINDS-OF-WORD-BOUNDARIES");
+    t!(test9: "XΣXΣ baffle" => "XΣXΣ-BAFFLE");
+    t!(test10: "XMLHttpRequest" => "XML-HTTP-REQUEST");
+    t!(test11: "SHOUTY-KEBAB-CASE" => "SHOUTY-KEBAB-CASE");
+}
diff --git a/0.3.3/src/shouty_snake.rs b/0.3.3/src/shouty_snake.rs
new file mode 100644
index 0000000..8f4289a
--- /dev/null
+++ b/0.3.3/src/shouty_snake.rs
@@ -0,0 +1,64 @@
+use crate::{transform, uppercase};
+
+/// This trait defines a shouty snake case conversion.
+///
+/// In SHOUTY_SNAKE_CASE, word boundaries are indicated by underscores and all
+/// words are in uppercase.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ShoutySnakeCase;
+///     
+/// let sentence = "That world is growing in this minute.";
+/// assert_eq!(sentence.to_shouty_snake_case(), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
+/// ```
+pub trait ShoutySnakeCase: ToOwned {
+    /// Convert this type to shouty snake case.
+    fn to_shouty_snake_case(&self) -> Self::Owned;
+}
+
+/// Oh heck, ShoutySnekCase is an alias for ShoutySnakeCase. See ShoutySnakeCase
+/// for more documentation.
+pub trait ShoutySnekCase: ToOwned {
+    /// CONVERT THIS TYPE TO SNEK CASE.
+    #[allow(non_snake_case)]
+    fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned;
+}
+
+impl<T: ?Sized + ShoutySnakeCase> ShoutySnekCase for T {
+    fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned {
+        self.to_shouty_snake_case()
+    }
+}
+
+impl ShoutySnakeCase for str {
+    fn to_shouty_snake_case(&self) -> Self::Owned {
+        transform(self, uppercase, |s| s.push('_'))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ShoutySnakeCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_shouty_snake_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "CAMEL_CASE");
+    t!(test2: "This is Human case." => "THIS_IS_HUMAN_CASE");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED_UP_CAMEL_CASE_WITH_SOME_SPACES");
+    t!(test4: "mixed_up_snake_case with some _spaces" => "MIXED_UP_SNAKE_CASE_WITH_SOME_SPACES");
+    t!(test5: "kebab-case" => "KEBAB_CASE");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY_SNAKE_CASE");
+    t!(test7: "snake_case" => "SNAKE_CASE");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS_CONTAINS_ALL_KINDS_OF_WORD_BOUNDARIES");
+    t!(test9: "XΣXΣ baffle" => "XΣXΣ_BAFFLE");
+    t!(test10: "XMLHttpRequest" => "XML_HTTP_REQUEST");
+}
diff --git a/0.3.3/src/snake.rs b/0.3.3/src/snake.rs
new file mode 100644
index 0000000..c1ad376
--- /dev/null
+++ b/0.3.3/src/snake.rs
@@ -0,0 +1,77 @@
+use crate::{lowercase, transform};
+
+/// This trait defines a snake case conversion.
+///
+/// In snake_case, word boundaries are indicated by underscores.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::SnakeCase;
+///
+/// let sentence = "We carry a new world here, in our hearts.";
+/// assert_eq!(sentence.to_snake_case(), "we_carry_a_new_world_here_in_our_hearts");
+/// ```
+pub trait SnakeCase: ToOwned {
+    /// Convert this type to snake case.
+    fn to_snake_case(&self) -> Self::Owned;
+}
+
+/// Oh heck, SnekCase is an alias for SnakeCase. See SnakeCase for
+/// more documentation.
+pub trait SnekCase: ToOwned {
+    /// Convert this type to snek case.
+    fn to_snek_case(&self) -> Self::Owned;
+}
+
+impl<T: ?Sized + SnakeCase> SnekCase for T {
+    fn to_snek_case(&self) -> Self::Owned {
+        self.to_snake_case()
+    }
+}
+
+impl SnakeCase for str {
+    fn to_snake_case(&self) -> String {
+        transform(self, lowercase, |s| s.push('_'))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::SnakeCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_snake_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "camel_case");
+    t!(test2: "This is Human case." => "this_is_human_case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed_up_camel_case_with_some_spaces");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed_up_snake_case_with_some_spaces");
+    t!(test5: "kebab-case" => "kebab_case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "shouty_snake_case");
+    t!(test7: "snake_case" => "snake_case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this_contains_all_kinds_of_word_boundaries");
+    t!(test9: "XΣXΣ baffle" => "xσxς_baffle");
+    t!(test10: "XMLHttpRequest" => "xml_http_request");
+    t!(test11: "FIELD_NAME11" => "field_name11");
+    t!(test12: "99BOTTLES" => "99bottles");
+    t!(test13: "FieldNamE11" => "field_nam_e11");
+
+    t!(test14: "abc123def456" => "abc123def456");
+    t!(test16: "abc123DEF456" => "abc123_def456");
+    t!(test17: "abc123Def456" => "abc123_def456");
+    t!(test18: "abc123DEf456" => "abc123_d_ef456");
+    t!(test19: "ABC123def456" => "abc123def456");
+    t!(test20: "ABC123DEF456" => "abc123def456");
+    t!(test21: "ABC123Def456" => "abc123_def456");
+    t!(test22: "ABC123DEf456" => "abc123d_ef456");
+    t!(test23: "ABC123dEEf456FOO" => "abc123d_e_ef456_foo");
+    t!(test24: "abcDEF" => "abc_def");
+    t!(test25: "ABcDE" => "a_bc_de");
+}
diff --git a/0.3.3/src/title.rs b/0.3.3/src/title.rs
new file mode 100644
index 0000000..015a9fa
--- /dev/null
+++ b/0.3.3/src/title.rs
@@ -0,0 +1,50 @@
+use crate::{capitalize, transform};
+
+/// This trait defines a title case conversion.
+///
+/// In Title Case, word boundaries are indicated by spaces, and every word is
+/// capitalized.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::TitleCase;
+///
+/// let sentence = "We have always lived in slums and holes in the wall.";
+/// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall");
+/// ```
+pub trait TitleCase: ToOwned {
+    /// Convert this type to title case.
+    fn to_title_case(&self) -> Self::Owned;
+}
+
+impl TitleCase for str {
+    fn to_title_case(&self) -> String {
+        transform(self, capitalize, |s| s.push(' '))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::TitleCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_title_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "Camel Case");
+    t!(test2: "This is Human case." => "This Is Human Case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed Up Camel Case With Some Spaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "Mixed Up Snake Case With Some Spaces");
+    t!(test5: "kebab-case" => "Kebab Case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case");
+    t!(test7: "snake_case" => "Snake Case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries");
+    t!(test9: "XΣXΣ baffle" => "Xσxς Baffle");
+    t!(test10: "XMLHttpRequest" => "Xml Http Request");
+}
diff --git a/Android.bp b/Android.bp
index 0d8524e..b3de44e 100644
--- a/Android.bp
+++ b/Android.bp
@@ -42,7 +42,7 @@ rust_test {
     host_supported: true,
     crate_name: "heck",
     cargo_env_compat: true,
-    cargo_pkg_version: "0.3.3",
+    cargo_pkg_version: "0.4.1",
     srcs: ["src/lib.rs"],
     test_suites: ["general-tests"],
     auto_gen_config: true,
@@ -50,6 +50,10 @@ rust_test {
         unit_test: true,
     },
     edition: "2018",
+    features: [
+        "unicode",
+        "unicode-segmentation",
+    ],
     rustlibs: [
         "libunicode_segmentation",
     ],
@@ -60,10 +64,20 @@ rust_library {
     host_supported: true,
     crate_name: "heck",
     cargo_env_compat: true,
-    cargo_pkg_version: "0.3.3",
+    cargo_pkg_version: "0.4.1",
     srcs: ["src/lib.rs"],
     edition: "2018",
+    features: [
+        "unicode",
+        "unicode-segmentation",
+    ],
     rustlibs: [
         "libunicode_segmentation",
     ],
+    apex_available: [
+        "//apex_available:platform",
+        "//apex_available:anyapex",
+    ],
+    product_available: true,
+    vendor_available: true,
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..c0f2f24
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,17 @@
+# 0.4.1
+
+Improvements:
+
+- Add Train-Case support
+
+# 0.4.0
+
+Breaking changes:
+
+* Make unicode support optional (off by default). Enable the `unicode` crate
+  feature if you need unicode support.
+* Rename all traits from `SomeCase` to `ToSomeCase`, matching `std`s convention
+  of beginning trait names with a verb (`ToOwned`, `AsRef`, …)
+* Rename `ToMixedCase` to `ToLowerCamelCase`
+* Rename `ToCamelCase` to `ToUpperCamelCase`
+* Add `ToPascalCase` as an alias to `ToUpperCamelCase`
diff --git a/Cargo.toml b/Cargo.toml
index fc9c28d..7990368 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,25 +3,41 @@
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
 # with all versions of Cargo and also rewrite `path` dependencies
-# to registry (e.g., crates.io) dependencies
+# to registry (e.g., crates.io) dependencies.
 #
-# If you believe there's an error in this file please file an
-# issue against the rust-lang/cargo repository. If you're
-# editing this file be aware that the upstream Cargo.toml
-# will likely look very different (and much more reasonable)
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
 
 [package]
 edition = "2018"
 name = "heck"
-version = "0.3.3"
+version = "0.4.1"
 authors = ["Without Boats <woboats@gmail.com>"]
-include = ["src/**/*", "LICENSE-*", "README.md", "CHANGELOG.md"]
+include = [
+    "src/**/*",
+    "LICENSE-*",
+    "README.md",
+    "CHANGELOG.md",
+]
 description = "heck is a case conversion library."
 homepage = "https://github.com/withoutboats/heck"
 documentation = "https://docs.rs/heck"
 readme = "README.md"
-keywords = ["string", "case", "camel", "snake", "unicode"]
+keywords = [
+    "string",
+    "case",
+    "camel",
+    "snake",
+    "unicode",
+]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/withoutboats/heck"
+
 [dependencies.unicode-segmentation]
 version = "1.2.0"
+optional = true
+
+[features]
+default = []
+unicode = ["unicode-segmentation"]
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 80acd39..2ad25de 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,7 +1,7 @@
 [package]
 authors = ["Without Boats <woboats@gmail.com>"]
 name = "heck"
-version = "0.3.3"
+version = "0.4.1"
 edition = "2018"
 license = "MIT OR Apache-2.0"
 description = "heck is a case conversion library."
@@ -12,5 +12,9 @@ keywords = ["string", "case", "camel", "snake", "unicode"]
 readme = "README.md"
 include = ["src/**/*", "LICENSE-*", "README.md", "CHANGELOG.md"]
 
+[features]
+default = []
+unicode = ["unicode-segmentation"]
+
 [dependencies]
-unicode-segmentation = "1.2.0"
+unicode-segmentation = { version = "1.2.0", optional = true }
diff --git a/METADATA b/METADATA
index dd9970c..7f8d66f 100644
--- a/METADATA
+++ b/METADATA
@@ -1,3 +1,7 @@
+# This project was upgraded with external_updater.
+# Usage: tools/external_updater/updater.sh update rust/crates/heck
+# For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md
+
 name: "heck"
 description: "heck is a case conversion library."
 third_party {
@@ -7,13 +11,13 @@ third_party {
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/heck/heck-0.3.3.crate"
+    value: "https://static.crates.io/crates/heck/heck-0.4.1.crate"
   }
-  version: "0.3.3"
+  version: "0.4.1"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2021
-    month: 6
-    day: 21
+    year: 2023
+    month: 2
+    day: 16
   }
 }
diff --git a/OWNERS b/OWNERS
index 46fc303..45dc4dd 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1 +1 @@
-include platform/prebuilts/rust:/OWNERS
+include platform/prebuilts/rust:master:/OWNERS
diff --git a/README.md b/README.md
index 33f2a5d..5e052e7 100644
--- a/README.md
+++ b/README.md
@@ -30,13 +30,14 @@ indicators are dropped, except insofar as CamelCase capitalizes the first word.
 
 ## Cases contained in this library:
 
-1. CamelCase
-2. snake_case
-3. kebab-case
-4. SHOUTY_SNAKE_CASE
-5. mixedCase
+1. UpperCamelCase
+2. lowerCamelCase
+3. snake_case
+4. kebab-case
+5. SHOUTY_SNAKE_CASE
 6. Title Case
 7. SHOUTY-KEBAB-CASE
+8. Train-Case
 
 ## Contributing
 
diff --git a/TEST_MAPPING b/TEST_MAPPING
index e5f5c4c..3eb1d29 100644
--- a/TEST_MAPPING
+++ b/TEST_MAPPING
@@ -5,23 +5,40 @@
       "path": "external/rust/crates/argh"
     },
     {
-      "path": "external/rust/crates/base64"
-    }
-  ],
-  "presubmit": [
+      "path": "external/rust/crates/heck/0.3.3"
+    },
     {
-      "name": "authfs_device_test_src_lib"
+      "path": "external/rust/crates/libsqlite3-sys"
     },
     {
-      "name": "heck_test_src_lib"
-    }
-  ],
-  "presubmit-rust": [
+      "path": "packages/modules/Virtualization/apkdmverity"
+    },
+    {
+      "path": "packages/modules/Virtualization/authfs"
+    },
+    {
+      "path": "packages/modules/Virtualization/avmd"
+    },
+    {
+      "path": "packages/modules/Virtualization/encryptedstore"
+    },
+    {
+      "path": "packages/modules/Virtualization/virtualizationmanager"
+    },
+    {
+      "path": "packages/modules/Virtualization/vm"
+    },
+    {
+      "path": "packages/modules/Virtualization/zipfuse"
+    },
+    {
+      "path": "system/security/diced"
+    },
     {
-      "name": "authfs_device_test_src_lib"
+      "path": "system/security/keystore2"
     },
     {
-      "name": "heck_test_src_lib"
+      "path": "system/security/keystore2/legacykeystore"
     }
   ]
 }
diff --git a/cargo2android.json b/cargo2android.json
index d36fb44..5f2af9d 100644
--- a/cargo2android.json
+++ b/cargo2android.json
@@ -1,5 +1,6 @@
 {
   "device": true,
   "run": true,
-  "tests": true
-}
\ No newline at end of file
+  "tests": true,
+  "features": "unicode"
+}
diff --git a/patches/heck-0.3.3.diff b/patches/heck-0.3.3.diff
new file mode 100644
index 0000000..9ab6d50
--- /dev/null
+++ b/patches/heck-0.3.3.diff
@@ -0,0 +1,1164 @@
+diff --git a/0.3.3/Android.bp b/0.3.3/Android.bp
+new file mode 100644
+index 0000000..65601b5
+--- /dev/null
++++ b/0.3.3/Android.bp
+@@ -0,0 +1,69 @@
++// This file is generated by cargo2android.py --config cargo2android.json.
++// Do not modify this file as changes will be overridden on upgrade.
++
++package {
++    default_applicable_licenses: ["external_rust_crates_heck_license_0_3_3"],
++}
++
++// Added automatically by a large-scale-change that took the approach of
++// 'apply every license found to every target'. While this makes sure we respect
++// every license restriction, it may not be entirely correct.
++//
++// e.g. GPL in an MIT project might only apply to the contrib/ directory.
++//
++// Please consider splitting the single license below into multiple licenses,
++// taking care not to lose any license_kind information, and overriding the
++// default license using the 'licenses: [...]' property on targets as needed.
++//
++// For unused files, consider creating a 'fileGroup' with "//visibility:private"
++// to attach the license to, and including a comment whether the files may be
++// used in the current project.
++//
++// large-scale-change included anything that looked like it might be a license
++// text as a license_text. e.g. LICENSE, NOTICE, COPYING etc.
++//
++// Please consider removing redundant or irrelevant files from 'license_text:'.
++// See: http://go/android-license-faq
++license {
++    name: "external_rust_crates_heck_license_0_3_3",
++    visibility: [":__subpackages__"],
++    license_kinds: [
++        "SPDX-license-identifier-Apache-2.0",
++        "SPDX-license-identifier-MIT",
++    ],
++    license_text: [
++        "LICENSE-APACHE",
++        "LICENSE-MIT",
++    ],
++}
++
++rust_test {
++    name: "heck_test_src_lib_deprecated",
++    host_supported: true,
++    crate_name: "heck",
++    cargo_env_compat: true,
++    cargo_pkg_version: "0.3.3",
++    srcs: ["src/lib.rs"],
++    test_suites: ["general-tests"],
++    auto_gen_config: true,
++    test_options: {
++        unit_test: true,
++    },
++    edition: "2018",
++    rustlibs: [
++        "libunicode_segmentation",
++    ],
++}
++
++rust_library {
++    name: "libheck_deprecated",
++    host_supported: true,
++    crate_name: "heck",
++    cargo_env_compat: true,
++    cargo_pkg_version: "0.3.3",
++    srcs: ["src/lib.rs"],
++    edition: "2018",
++    rustlibs: [
++        "libunicode_segmentation",
++    ],
++}
+diff --git a/0.3.3/Cargo.toml b/0.3.3/Cargo.toml
+new file mode 100644
+index 0000000..fc9c28d
+--- /dev/null
++++ b/0.3.3/Cargo.toml
+@@ -0,0 +1,27 @@
++# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
++#
++# When uploading crates to the registry Cargo will automatically
++# "normalize" Cargo.toml files for maximal compatibility
++# with all versions of Cargo and also rewrite `path` dependencies
++# to registry (e.g., crates.io) dependencies
++#
++# If you believe there's an error in this file please file an
++# issue against the rust-lang/cargo repository. If you're
++# editing this file be aware that the upstream Cargo.toml
++# will likely look very different (and much more reasonable)
++
++[package]
++edition = "2018"
++name = "heck"
++version = "0.3.3"
++authors = ["Without Boats <woboats@gmail.com>"]
++include = ["src/**/*", "LICENSE-*", "README.md", "CHANGELOG.md"]
++description = "heck is a case conversion library."
++homepage = "https://github.com/withoutboats/heck"
++documentation = "https://docs.rs/heck"
++readme = "README.md"
++keywords = ["string", "case", "camel", "snake", "unicode"]
++license = "MIT OR Apache-2.0"
++repository = "https://github.com/withoutboats/heck"
++[dependencies.unicode-segmentation]
++version = "1.2.0"
+diff --git a/0.3.3/Cargo.toml.orig b/0.3.3/Cargo.toml.orig
+new file mode 100644
+index 0000000..80acd39
+--- /dev/null
++++ b/0.3.3/Cargo.toml.orig
+@@ -0,0 +1,16 @@
++[package]
++authors = ["Without Boats <woboats@gmail.com>"]
++name = "heck"
++version = "0.3.3"
++edition = "2018"
++license = "MIT OR Apache-2.0"
++description = "heck is a case conversion library."
++homepage = "https://github.com/withoutboats/heck"
++repository = "https://github.com/withoutboats/heck"
++documentation = "https://docs.rs/heck"
++keywords = ["string", "case", "camel", "snake", "unicode"]
++readme = "README.md"
++include = ["src/**/*", "LICENSE-*", "README.md", "CHANGELOG.md"]
++
++[dependencies]
++unicode-segmentation = "1.2.0"
+diff --git a/0.3.3/LICENSE b/0.3.3/LICENSE
+new file mode 120000
+index 0000000..6b579aa
+--- /dev/null
++++ b/0.3.3/LICENSE
+@@ -0,0 +1 @@
++LICENSE-APACHE
+\ No newline at end of file
+diff --git a/0.3.3/LICENSE-APACHE b/0.3.3/LICENSE-APACHE
+new file mode 100644
+index 0000000..16fe87b
+--- /dev/null
++++ b/0.3.3/LICENSE-APACHE
+@@ -0,0 +1,201 @@
++                              Apache License
++                        Version 2.0, January 2004
++                     http://www.apache.org/licenses/
++
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++   the conditions stated in this License.
++
++5. Submission of Contributions. Unless You explicitly state otherwise,
++   any Contribution intentionally submitted for inclusion in the Work
++   by You to the Licensor shall be under the terms and conditions of
++   this License, without any additional terms or conditions.
++   Notwithstanding the above, nothing herein shall supersede or modify
++   the terms of any separate license agreement you may have executed
++   with Licensor regarding such Contributions.
++
++6. Trademarks. This License does not grant permission to use the trade
++   names, trademarks, service marks, or product names of the Licensor,
++   except as required for reasonable and customary use in describing the
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++7. Disclaimer of Warranty. Unless required by applicable law or
++   agreed to in writing, Licensor provides the Work (and each
++   Contributor provides its Contributions) on an "AS IS" BASIS,
++   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
++   implied, including, without limitation, any warranties or conditions
++   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
++   PARTICULAR PURPOSE. You are solely responsible for determining the
++   appropriateness of using or redistributing the Work and assume any
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++
++8. Limitation of Liability. In no event and under no legal theory,
++   whether in tort (including negligence), contract, or otherwise,
++   unless required by applicable law (such as deliberate and grossly
++   negligent acts) or agreed to in writing, shall any Contributor be
++   liable to You for damages, including any direct, indirect, special,
++   incidental, or consequential damages of any character arising as a
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++   on Your own behalf and on Your sole responsibility, not on behalf
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++APPENDIX: How to apply the Apache License to your work.
++
++   To apply the Apache License to your work, attach the following
++   boilerplate notice, with the fields enclosed by brackets "[]"
++   replaced with your own identifying information. (Don't include
++   the brackets!)  The text should be enclosed in the appropriate
++   comment syntax for the file format. We also recommend that a
++   file or class name and description of purpose be included on the
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++Licensed under the Apache License, Version 2.0 (the "License");
++you may not use this file except in compliance with the License.
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++
++Unless required by applicable law or agreed to in writing, software
++distributed under the License is distributed on an "AS IS" BASIS,
++WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
++See the License for the specific language governing permissions and
++limitations under the License.
+diff --git a/0.3.3/LICENSE-MIT b/0.3.3/LICENSE-MIT
+new file mode 100644
+index 0000000..e69282e
+--- /dev/null
++++ b/0.3.3/LICENSE-MIT
+@@ -0,0 +1,25 @@
++Copyright (c) 2015 The Rust Project Developers
++
++Permission is hereby granted, free of charge, to any
++person obtaining a copy of this software and associated
++documentation files (the "Software"), to deal in the
++Software without restriction, including without
++limitation the rights to use, copy, modify, merge,
++publish, distribute, sublicense, and/or sell copies of
++the Software, and to permit persons to whom the Software
++is furnished to do so, subject to the following
++conditions:
++
++The above copyright notice and this permission notice
++shall be included in all copies or substantial portions
++of the Software.
++
++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
++ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
++TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
++PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
++SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
++CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
++OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
++IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
++DEALINGS IN THE SOFTWARE.
+diff --git a/0.3.3/METADATA b/0.3.3/METADATA
+new file mode 100644
+index 0000000..dd9970c
+--- /dev/null
++++ b/0.3.3/METADATA
+@@ -0,0 +1,19 @@
++name: "heck"
++description: "heck is a case conversion library."
++third_party {
++  url {
++    type: HOMEPAGE
++    value: "https://crates.io/crates/heck"
++  }
++  url {
++    type: ARCHIVE
++    value: "https://static.crates.io/crates/heck/heck-0.3.3.crate"
++  }
++  version: "0.3.3"
++  license_type: NOTICE
++  last_upgrade_date {
++    year: 2021
++    month: 6
++    day: 21
++  }
++}
+diff --git a/0.3.3/MODULE_LICENSE_APACHE2 b/0.3.3/MODULE_LICENSE_APACHE2
+new file mode 100644
+index 0000000..e69de29
+diff --git a/0.3.3/NOTICE b/0.3.3/NOTICE
+new file mode 120000
+index 0000000..7a694c9
+--- /dev/null
++++ b/0.3.3/NOTICE
+@@ -0,0 +1 @@
++LICENSE
+\ No newline at end of file
+diff --git a/0.3.3/OWNERS b/0.3.3/OWNERS
+new file mode 100644
+index 0000000..46fc303
+--- /dev/null
++++ b/0.3.3/OWNERS
+@@ -0,0 +1 @@
++include platform/prebuilts/rust:/OWNERS
+diff --git a/0.3.3/README.md b/0.3.3/README.md
+new file mode 100644
+index 0000000..33f2a5d
+--- /dev/null
++++ b/0.3.3/README.md
+@@ -0,0 +1,63 @@
++# **heck** is a case conversion library
++
++!["I specifically requested the opposite of this."](./no_step_on_snek.png)
++
++This library exists to provide case conversion between common cases like
++CamelCase and snake_case. It is intended to be unicode aware, internally
++consistent, and reasonably well performing.
++
++## Definition of a word boundary
++
++Word boundaries are defined as the "unicode words" defined in the
++`unicode_segmentation` library, as well as within those words in this manner:
++
++1. All underscore characters are considered word boundaries.
++2. If an uppercase character is followed by lowercase letters, a word boundary
++is considered to be just prior to that uppercase character.
++3. If multiple uppercase characters are consecutive, they are considered to be
++within a single word, except that the last will be part of the next word if it
++is followed by lowercase characters (see rule 2).
++
++That is, "HelloWorld" is segmented `Hello|World` whereas "XMLHttpRequest" is
++segmented `XML|Http|Request`.
++
++Characters not within words (such as spaces, punctuations, and underscores)
++are not included in the output string except as they are a part of the case
++being converted to. Multiple adjacent word boundaries (such as a series of
++underscores) are folded into one. ("hello__world" in snake case is therefore
++"hello_world", not the exact same string). Leading or trailing word boundary
++indicators are dropped, except insofar as CamelCase capitalizes the first word.
++
++## Cases contained in this library:
++
++1. CamelCase
++2. snake_case
++3. kebab-case
++4. SHOUTY_SNAKE_CASE
++5. mixedCase
++6. Title Case
++7. SHOUTY-KEBAB-CASE
++
++## Contributing
++
++PRs of additional well-established cases welcome.
++
++This library is a little bit opinionated (dropping punctuation, for example).
++If that doesn't fit your use case, I hope there is another crate that does. I
++would prefer **not** to receive PRs to make this behavior more configurable.
++
++Bug reports & fixes always welcome. :-)
++
++## MSRV
++
++The minimum supported Rust version for this crate is 1.32.0. This may change in
++minor or patch releases, but we probably won't ever require a very recent
++version. If you would like to have a stronger guarantee than that, please open
++an issue.
++
++## License
++
++heck is distributed under the terms of both the MIT license and the
++Apache License (Version 2.0).
++
++See LICENSE-APACHE and LICENSE-MIT for details.
+diff --git a/0.3.3/TEST_MAPPING b/0.3.3/TEST_MAPPING
+new file mode 100644
+index 0000000..e5f5c4c
+--- /dev/null
++++ b/0.3.3/TEST_MAPPING
+@@ -0,0 +1,27 @@
++// Generated by update_crate_tests.py for tests that depend on this crate.
++{
++  "imports": [
++    {
++      "path": "external/rust/crates/argh"
++    },
++    {
++      "path": "external/rust/crates/base64"
++    }
++  ],
++  "presubmit": [
++    {
++      "name": "authfs_device_test_src_lib"
++    },
++    {
++      "name": "heck_test_src_lib"
++    }
++  ],
++  "presubmit-rust": [
++    {
++      "name": "authfs_device_test_src_lib"
++    },
++    {
++      "name": "heck_test_src_lib"
++    }
++  ]
++}
+diff --git a/0.3.3/cargo2android.json b/0.3.3/cargo2android.json
+new file mode 100644
+index 0000000..d36fb44
+--- /dev/null
++++ b/0.3.3/cargo2android.json
+@@ -0,0 +1,5 @@
++{
++  "device": true,
++  "run": true,
++  "tests": true
++}
+\ No newline at end of file
+diff --git a/0.3.3/src/camel.rs b/0.3.3/src/camel.rs
+new file mode 100644
+index 0000000..6949435
+--- /dev/null
++++ b/0.3.3/src/camel.rs
+@@ -0,0 +1,50 @@
++use crate::{capitalize, transform};
++
++/// This trait defines a camel case conversion.
++///
++/// In CamelCase, word boundaries are indicated by capital letters, including
++/// the first word.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::CamelCase;
++///
++/// let sentence = "We are not in the least afraid of ruins.";
++/// assert_eq!(sentence.to_camel_case(), "WeAreNotInTheLeastAfraidOfRuins");
++/// ```
++pub trait CamelCase: ToOwned {
++    /// Convert this type to camel case.
++    fn to_camel_case(&self) -> Self::Owned;
++}
++
++impl CamelCase for str {
++    fn to_camel_case(&self) -> String {
++        transform(self, capitalize, |_| {})
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::CamelCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_camel_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "CamelCase");
++    t!(test2: "This is Human case." => "ThisIsHumanCase");
++    t!(test3: "MixedUP_CamelCase, with some Spaces" => "MixedUpCamelCaseWithSomeSpaces");
++    t!(test4: "mixed_up_ snake_case, with some _spaces" => "MixedUpSnakeCaseWithSomeSpaces");
++    t!(test5: "kebab-case" => "KebabCase");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "ShoutySnakeCase");
++    t!(test7: "snake_case" => "SnakeCase");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "ThisContainsAllKindsOfWordBoundaries");
++    t!(test9: "XΣXΣ baffle" => "XσxςBaffle");
++    t!(test10: "XMLHttpRequest" => "XmlHttpRequest");
++}
+diff --git a/0.3.3/src/kebab.rs b/0.3.3/src/kebab.rs
+new file mode 100644
+index 0000000..75e5978
+--- /dev/null
++++ b/0.3.3/src/kebab.rs
+@@ -0,0 +1,49 @@
++use crate::{lowercase, transform};
++
++/// This trait defines a kebab case conversion.
++///
++/// In kebab-case, word boundaries are indicated by hyphens.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::KebabCase;
++///
++/// let sentence = "We are going to inherit the earth.";
++/// assert_eq!(sentence.to_kebab_case(), "we-are-going-to-inherit-the-earth");
++/// ```
++pub trait KebabCase: ToOwned {
++    /// Convert this type to kebab case.
++    fn to_kebab_case(&self) -> Self::Owned;
++}
++
++impl KebabCase for str {
++    fn to_kebab_case(&self) -> Self::Owned {
++        transform(self, lowercase, |s| s.push('-'))
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::KebabCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_kebab_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "camel-case");
++    t!(test2: "This is Human case." => "this-is-human-case");
++    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed-up-camel-case-with-some-spaces");
++    t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed-up-snake-case-with-some-spaces");
++    t!(test5: "kebab-case" => "kebab-case");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "shouty-snake-case");
++    t!(test7: "snake_case" => "snake-case");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this-contains-all-kinds-of-word-boundaries");
++    t!(test9: "XΣXΣ baffle" => "xσxς-baffle");
++    t!(test10: "XMLHttpRequest" => "xml-http-request");
++}
+diff --git a/0.3.3/src/lib.rs b/0.3.3/src/lib.rs
+new file mode 100644
+index 0000000..00a9fbe
+--- /dev/null
++++ b/0.3.3/src/lib.rs
+@@ -0,0 +1,181 @@
++//! **heck** is a case conversion library.
++//!
++//! This library exists to provide case conversion between common cases like
++//! CamelCase and snake_case. It is intended to be unicode aware, internally,
++//! consistent, and reasonably well performing.
++//!
++//! ## Definition of a word boundary
++//!
++//! Word boundaries are defined as the "unicode words" defined in the
++//! `unicode_segmentation` library, as well as within those words in this
++//! manner:
++//!
++//! 1. All underscore characters are considered word boundaries.
++//! 2. If an uppercase character is followed by lowercase letters, a word
++//! boundary is considered to be just prior to that uppercase character.
++//! 3. If multiple uppercase characters are consecutive, they are considered to
++//! be within a single word, except that the last will be part of the next word
++//! if it is followed by lowercase characters (see rule 2).
++//!
++//! That is, "HelloWorld" is segmented `Hello|World` whereas "XMLHttpRequest" is
++//! segmented `XML|Http|Request`.
++//!
++//! Characters not within words (such as spaces, punctuations, and underscores)
++//! are not included in the output string except as they are a part of the case
++//! being converted to. Multiple adjacent word boundaries (such as a series of
++//! underscores) are folded into one. ("hello__world" in snake case is therefore
++//! "hello_world", not the exact same string). Leading or trailing word boundary
++//! indicators are dropped, except insofar as CamelCase capitalizes the first
++//! word.
++//!
++//! ### Cases contained in this library:
++//!
++//! 1. CamelCase
++//! 2. snake_case
++//! 3. kebab-case
++//! 4. SHOUTY_SNAKE_CASE
++//! 5. mixedCase
++//! 6. Title Case
++//! 7. SHOUTY-KEBAB-CASE
++#![deny(missing_docs)]
++
++mod camel;
++mod kebab;
++mod mixed;
++mod shouty_kebab;
++mod shouty_snake;
++mod snake;
++mod title;
++
++pub use camel::CamelCase;
++pub use kebab::KebabCase;
++pub use mixed::MixedCase;
++pub use shouty_kebab::ShoutyKebabCase;
++pub use shouty_snake::{ShoutySnakeCase, ShoutySnekCase};
++pub use snake::{SnakeCase, SnekCase};
++pub use title::TitleCase;
++
++use unicode_segmentation::UnicodeSegmentation;
++
++fn transform<F, G>(s: &str, with_word: F, boundary: G) -> String
++where
++    F: Fn(&str, &mut String),
++    G: Fn(&mut String),
++{
++    /// Tracks the current 'mode' of the transformation algorithm as it scans
++    /// the input string.
++    ///
++    /// The mode is a tri-state which tracks the case of the last cased
++    /// character of the current word. If there is no cased character
++    /// (either lowercase or uppercase) since the previous word boundary,
++    /// than the mode is `Boundary`. If the last cased character is lowercase,
++    /// then the mode is `Lowercase`. Othertherwise, the mode is
++    /// `Uppercase`.
++    #[derive(Clone, Copy, PartialEq)]
++    enum WordMode {
++        /// There have been no lowercase or uppercase characters in the current
++        /// word.
++        Boundary,
++        /// The previous cased character in the current word is lowercase.
++        Lowercase,
++        /// The previous cased character in the current word is uppercase.
++        Uppercase,
++    }
++
++    let mut out = String::new();
++    let mut first_word = true;
++
++    for word in s.unicode_words() {
++        let mut char_indices = word.char_indices().peekable();
++        let mut init = 0;
++        let mut mode = WordMode::Boundary;
++
++        while let Some((i, c)) = char_indices.next() {
++            // Skip underscore characters
++            if c == '_' {
++                if init == i {
++                    init += 1;
++                }
++                continue;
++            }
++
++            if let Some(&(next_i, next)) = char_indices.peek() {
++                // The mode including the current character, assuming the
++                // current character does not result in a word boundary.
++                let next_mode = if c.is_lowercase() {
++                    WordMode::Lowercase
++                } else if c.is_uppercase() {
++                    WordMode::Uppercase
++                } else {
++                    mode
++                };
++
++                // Word boundary after if next is underscore or current is
++                // not uppercase and next is uppercase
++                if next == '_' || (next_mode == WordMode::Lowercase && next.is_uppercase()) {
++                    if !first_word {
++                        boundary(&mut out);
++                    }
++                    with_word(&word[init..next_i], &mut out);
++                    first_word = false;
++                    init = next_i;
++                    mode = WordMode::Boundary;
++
++                // Otherwise if current and previous are uppercase and next
++                // is lowercase, word boundary before
++                } else if mode == WordMode::Uppercase && c.is_uppercase() && next.is_lowercase() {
++                    if !first_word {
++                        boundary(&mut out);
++                    } else {
++                        first_word = false;
++                    }
++                    with_word(&word[init..i], &mut out);
++                    init = i;
++                    mode = WordMode::Boundary;
++
++                // Otherwise no word boundary, just update the mode
++                } else {
++                    mode = next_mode;
++                }
++            } else {
++                // Collect trailing characters as a word
++                if !first_word {
++                    boundary(&mut out);
++                } else {
++                    first_word = false;
++                }
++                with_word(&word[init..], &mut out);
++                break;
++            }
++        }
++    }
++
++    out
++}
++
++fn lowercase(s: &str, out: &mut String) {
++    let mut chars = s.chars().peekable();
++    while let Some(c) = chars.next() {
++        if c == 'Σ' && chars.peek().is_none() {
++            out.push('ς');
++        } else {
++            out.extend(c.to_lowercase());
++        }
++    }
++}
++
++fn uppercase(s: &str, out: &mut String) {
++    for c in s.chars() {
++        out.extend(c.to_uppercase())
++    }
++}
++
++fn capitalize(s: &str, out: &mut String) {
++    let mut char_indices = s.char_indices();
++    if let Some((_, c)) = char_indices.next() {
++        out.extend(c.to_uppercase());
++        if let Some((i, _)) = char_indices.next() {
++            lowercase(&s[i..], out);
++        }
++    }
++}
+diff --git a/0.3.3/src/mixed.rs b/0.3.3/src/mixed.rs
+new file mode 100644
+index 0000000..71089f2
+--- /dev/null
++++ b/0.3.3/src/mixed.rs
+@@ -0,0 +1,61 @@
++use crate::{capitalize, lowercase, transform};
++
++/// This trait defines a mixed case conversion.
++///
++/// In mixedCase, word boundaries are indicated by capital letters, excepting
++/// the first word.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::MixedCase;
++///
++/// let sentence = "It is we who built these palaces and cities.";
++/// assert_eq!(sentence.to_mixed_case(), "itIsWeWhoBuiltThesePalacesAndCities");
++/// ```
++pub trait MixedCase: ToOwned {
++    /// Convert this type to mixed case.
++    fn to_mixed_case(&self) -> Self::Owned;
++}
++
++impl MixedCase for str {
++    fn to_mixed_case(&self) -> String {
++        transform(
++            self,
++            |s, out| {
++                if out.is_empty() {
++                    lowercase(s, out);
++                } else {
++                    capitalize(s, out)
++                }
++            },
++            |_| {},
++        )
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::MixedCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_mixed_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "camelCase");
++    t!(test2: "This is Human case." => "thisIsHumanCase");
++    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixedUpCamelCaseWithSomeSpaces");
++    t!(test4: "mixed_up_ snake_case, with some _spaces" => "mixedUpSnakeCaseWithSomeSpaces");
++    t!(test5: "kebab-case" => "kebabCase");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "shoutySnakeCase");
++    t!(test7: "snake_case" => "snakeCase");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "thisContainsAllKindsOfWordBoundaries");
++    t!(test9: "XΣXΣ baffle" => "xσxςBaffle");
++    t!(test10: "XMLHttpRequest" => "xmlHttpRequest");
++    // TODO unicode tests
++}
+diff --git a/0.3.3/src/shouty_kebab.rs b/0.3.3/src/shouty_kebab.rs
+new file mode 100644
+index 0000000..0225471
+--- /dev/null
++++ b/0.3.3/src/shouty_kebab.rs
+@@ -0,0 +1,51 @@
++use crate::{transform, uppercase};
++
++/// This trait defines a shouty kebab case conversion.
++///
++/// In SHOUTY-KEBAB-CASE, word boundaries are indicated by hyphens and all
++/// words are in uppercase.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::ShoutyKebabCase;
++///
++/// let sentence = "We are going to inherit the earth.";
++/// assert_eq!(sentence.to_shouty_kebab_case(), "WE-ARE-GOING-TO-INHERIT-THE-EARTH");
++/// ```
++pub trait ShoutyKebabCase: ToOwned {
++    /// Convert this type to shouty kebab case.
++    fn to_shouty_kebab_case(&self) -> Self::Owned;
++}
++
++impl ShoutyKebabCase for str {
++    fn to_shouty_kebab_case(&self) -> Self::Owned {
++        transform(self, uppercase, |s| s.push('-'))
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::ShoutyKebabCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_shouty_kebab_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "CAMEL-CASE");
++    t!(test2: "This is Human case." => "THIS-IS-HUMAN-CASE");
++    t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED-UP-CAMEL-CASE-WITH-SOME-SPACES");
++    t!(test4: "mixed_up_ snake_case with some _spaces" => "MIXED-UP-SNAKE-CASE-WITH-SOME-SPACES");
++    t!(test5: "kebab-case" => "KEBAB-CASE");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY-SNAKE-CASE");
++    t!(test7: "snake_case" => "SNAKE-CASE");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS-CONTAINS-ALL-KINDS-OF-WORD-BOUNDARIES");
++    t!(test9: "XΣXΣ baffle" => "XΣXΣ-BAFFLE");
++    t!(test10: "XMLHttpRequest" => "XML-HTTP-REQUEST");
++    t!(test11: "SHOUTY-KEBAB-CASE" => "SHOUTY-KEBAB-CASE");
++}
+diff --git a/0.3.3/src/shouty_snake.rs b/0.3.3/src/shouty_snake.rs
+new file mode 100644
+index 0000000..8f4289a
+--- /dev/null
++++ b/0.3.3/src/shouty_snake.rs
+@@ -0,0 +1,64 @@
++use crate::{transform, uppercase};
++
++/// This trait defines a shouty snake case conversion.
++///
++/// In SHOUTY_SNAKE_CASE, word boundaries are indicated by underscores and all
++/// words are in uppercase.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::ShoutySnakeCase;
++///     
++/// let sentence = "That world is growing in this minute.";
++/// assert_eq!(sentence.to_shouty_snake_case(), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
++/// ```
++pub trait ShoutySnakeCase: ToOwned {
++    /// Convert this type to shouty snake case.
++    fn to_shouty_snake_case(&self) -> Self::Owned;
++}
++
++/// Oh heck, ShoutySnekCase is an alias for ShoutySnakeCase. See ShoutySnakeCase
++/// for more documentation.
++pub trait ShoutySnekCase: ToOwned {
++    /// CONVERT THIS TYPE TO SNEK CASE.
++    #[allow(non_snake_case)]
++    fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned;
++}
++
++impl<T: ?Sized + ShoutySnakeCase> ShoutySnekCase for T {
++    fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned {
++        self.to_shouty_snake_case()
++    }
++}
++
++impl ShoutySnakeCase for str {
++    fn to_shouty_snake_case(&self) -> Self::Owned {
++        transform(self, uppercase, |s| s.push('_'))
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::ShoutySnakeCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_shouty_snake_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "CAMEL_CASE");
++    t!(test2: "This is Human case." => "THIS_IS_HUMAN_CASE");
++    t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED_UP_CAMEL_CASE_WITH_SOME_SPACES");
++    t!(test4: "mixed_up_snake_case with some _spaces" => "MIXED_UP_SNAKE_CASE_WITH_SOME_SPACES");
++    t!(test5: "kebab-case" => "KEBAB_CASE");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY_SNAKE_CASE");
++    t!(test7: "snake_case" => "SNAKE_CASE");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS_CONTAINS_ALL_KINDS_OF_WORD_BOUNDARIES");
++    t!(test9: "XΣXΣ baffle" => "XΣXΣ_BAFFLE");
++    t!(test10: "XMLHttpRequest" => "XML_HTTP_REQUEST");
++}
+diff --git a/0.3.3/src/snake.rs b/0.3.3/src/snake.rs
+new file mode 100644
+index 0000000..c1ad376
+--- /dev/null
++++ b/0.3.3/src/snake.rs
+@@ -0,0 +1,77 @@
++use crate::{lowercase, transform};
++
++/// This trait defines a snake case conversion.
++///
++/// In snake_case, word boundaries are indicated by underscores.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::SnakeCase;
++///
++/// let sentence = "We carry a new world here, in our hearts.";
++/// assert_eq!(sentence.to_snake_case(), "we_carry_a_new_world_here_in_our_hearts");
++/// ```
++pub trait SnakeCase: ToOwned {
++    /// Convert this type to snake case.
++    fn to_snake_case(&self) -> Self::Owned;
++}
++
++/// Oh heck, SnekCase is an alias for SnakeCase. See SnakeCase for
++/// more documentation.
++pub trait SnekCase: ToOwned {
++    /// Convert this type to snek case.
++    fn to_snek_case(&self) -> Self::Owned;
++}
++
++impl<T: ?Sized + SnakeCase> SnekCase for T {
++    fn to_snek_case(&self) -> Self::Owned {
++        self.to_snake_case()
++    }
++}
++
++impl SnakeCase for str {
++    fn to_snake_case(&self) -> String {
++        transform(self, lowercase, |s| s.push('_'))
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::SnakeCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_snake_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "camel_case");
++    t!(test2: "This is Human case." => "this_is_human_case");
++    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixed_up_camel_case_with_some_spaces");
++    t!(test4: "mixed_up_ snake_case with some _spaces" => "mixed_up_snake_case_with_some_spaces");
++    t!(test5: "kebab-case" => "kebab_case");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "shouty_snake_case");
++    t!(test7: "snake_case" => "snake_case");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this_contains_all_kinds_of_word_boundaries");
++    t!(test9: "XΣXΣ baffle" => "xσxς_baffle");
++    t!(test10: "XMLHttpRequest" => "xml_http_request");
++    t!(test11: "FIELD_NAME11" => "field_name11");
++    t!(test12: "99BOTTLES" => "99bottles");
++    t!(test13: "FieldNamE11" => "field_nam_e11");
++
++    t!(test14: "abc123def456" => "abc123def456");
++    t!(test16: "abc123DEF456" => "abc123_def456");
++    t!(test17: "abc123Def456" => "abc123_def456");
++    t!(test18: "abc123DEf456" => "abc123_d_ef456");
++    t!(test19: "ABC123def456" => "abc123def456");
++    t!(test20: "ABC123DEF456" => "abc123def456");
++    t!(test21: "ABC123Def456" => "abc123_def456");
++    t!(test22: "ABC123DEf456" => "abc123d_ef456");
++    t!(test23: "ABC123dEEf456FOO" => "abc123d_e_ef456_foo");
++    t!(test24: "abcDEF" => "abc_def");
++    t!(test25: "ABcDE" => "a_bc_de");
++}
+diff --git a/0.3.3/src/title.rs b/0.3.3/src/title.rs
+new file mode 100644
+index 0000000..015a9fa
+--- /dev/null
++++ b/0.3.3/src/title.rs
+@@ -0,0 +1,50 @@
++use crate::{capitalize, transform};
++
++/// This trait defines a title case conversion.
++///
++/// In Title Case, word boundaries are indicated by spaces, and every word is
++/// capitalized.
++///
++/// ## Example:
++///
++/// ```rust
++/// use heck::TitleCase;
++///
++/// let sentence = "We have always lived in slums and holes in the wall.";
++/// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall");
++/// ```
++pub trait TitleCase: ToOwned {
++    /// Convert this type to title case.
++    fn to_title_case(&self) -> Self::Owned;
++}
++
++impl TitleCase for str {
++    fn to_title_case(&self) -> String {
++        transform(self, capitalize, |s| s.push(' '))
++    }
++}
++
++#[cfg(test)]
++mod tests {
++    use super::TitleCase;
++
++    macro_rules! t {
++        ($t:ident : $s1:expr => $s2:expr) => {
++            #[test]
++            fn $t() {
++                assert_eq!($s1.to_title_case(), $s2)
++            }
++        };
++    }
++
++    t!(test1: "CamelCase" => "Camel Case");
++    t!(test2: "This is Human case." => "This Is Human Case");
++    t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed Up Camel Case With Some Spaces");
++    t!(test4: "mixed_up_ snake_case, with some _spaces" => "Mixed Up Snake Case With Some Spaces");
++    t!(test5: "kebab-case" => "Kebab Case");
++    t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case");
++    t!(test7: "snake_case" => "Snake Case");
++    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries");
++    t!(test9: "XΣXΣ baffle" => "Xσxς Baffle");
++    t!(test10: "XMLHttpRequest" => "Xml Http Request");
++}
diff --git a/src/kebab.rs b/src/kebab.rs
index 75e5978..6cce5a5 100644
--- a/src/kebab.rs
+++ b/src/kebab.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{lowercase, transform};
 
 /// This trait defines a kebab case conversion.
@@ -7,25 +9,43 @@ use crate::{lowercase, transform};
 /// ## Example:
 ///
 /// ```rust
-/// use heck::KebabCase;
+/// use heck::ToKebabCase;
 ///
 /// let sentence = "We are going to inherit the earth.";
 /// assert_eq!(sentence.to_kebab_case(), "we-are-going-to-inherit-the-earth");
 /// ```
-pub trait KebabCase: ToOwned {
+pub trait ToKebabCase: ToOwned {
     /// Convert this type to kebab case.
     fn to_kebab_case(&self) -> Self::Owned;
 }
 
-impl KebabCase for str {
+impl ToKebabCase for str {
     fn to_kebab_case(&self) -> Self::Owned {
-        transform(self, lowercase, |s| s.push('-'))
+        AsKebabCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a kebab case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(format!("{}", AsKebabCase(sentence)), "we-are-going-to-inherit-the-earth");
+/// ```
+pub struct AsKebabCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsKebabCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), lowercase, |f| write!(f, "-"), f)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::KebabCase;
+    use super::ToKebabCase;
 
     macro_rules! t {
         ($t:ident : $s1:expr => $s2:expr) => {
@@ -44,6 +64,7 @@ mod tests {
     t!(test6: "SHOUTY_SNAKE_CASE" => "shouty-snake-case");
     t!(test7: "snake_case" => "snake-case");
     t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this-contains-all-kinds-of-word-boundaries");
+    #[cfg(feature = "unicode")]
     t!(test9: "XΣXΣ baffle" => "xσxς-baffle");
     t!(test10: "XMLHttpRequest" => "xml-http-request");
 }
diff --git a/src/lib.rs b/src/lib.rs
index 00a9fbe..49bfb0e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,7 @@
 //! **heck** is a case conversion library.
 //!
 //! This library exists to provide case conversion between common cases like
-//! CamelCase and snake_case. It is intended to be unicode aware, internally,
+//! CamelCase and snake_case. It is intended to be unicode aware, internally
 //! consistent, and reasonably well performing.
 //!
 //! ## Definition of a word boundary
@@ -30,37 +30,60 @@
 //!
 //! ### Cases contained in this library:
 //!
-//! 1. CamelCase
-//! 2. snake_case
-//! 3. kebab-case
-//! 4. SHOUTY_SNAKE_CASE
-//! 5. mixedCase
+//! 1. UpperCamelCase
+//! 2. lowerCamelCase
+//! 3. snake_case
+//! 4. kebab-case
+//! 5. SHOUTY_SNAKE_CASE
 //! 6. Title Case
 //! 7. SHOUTY-KEBAB-CASE
+//! 8. Train-Case
 #![deny(missing_docs)]
+#![forbid(unsafe_code)]
 
-mod camel;
 mod kebab;
-mod mixed;
+mod lower_camel;
 mod shouty_kebab;
 mod shouty_snake;
 mod snake;
 mod title;
+mod train;
+mod upper_camel;
 
-pub use camel::CamelCase;
-pub use kebab::KebabCase;
-pub use mixed::MixedCase;
-pub use shouty_kebab::ShoutyKebabCase;
-pub use shouty_snake::{ShoutySnakeCase, ShoutySnekCase};
-pub use snake::{SnakeCase, SnekCase};
-pub use title::TitleCase;
+pub use kebab::{AsKebabCase, ToKebabCase};
+pub use lower_camel::{AsLowerCamelCase, ToLowerCamelCase};
+pub use shouty_kebab::{AsShoutyKebabCase, ToShoutyKebabCase};
+pub use shouty_snake::{
+    AsShoutySnakeCase, AsShoutySnakeCase as AsShoutySnekCase, ToShoutySnakeCase, ToShoutySnekCase,
+};
+pub use snake::{AsSnakeCase, AsSnakeCase as AsSnekCase, ToSnakeCase, ToSnekCase};
+pub use title::{AsTitleCase, ToTitleCase};
+pub use train::{AsTrainCase, ToTrainCase};
+pub use upper_camel::{
+    AsUpperCamelCase, AsUpperCamelCase as AsPascalCase, ToPascalCase, ToUpperCamelCase,
+};
 
-use unicode_segmentation::UnicodeSegmentation;
+use std::fmt;
 
-fn transform<F, G>(s: &str, with_word: F, boundary: G) -> String
+#[cfg(feature = "unicode")]
+fn get_iterator(s: &str) -> unicode_segmentation::UnicodeWords {
+    use unicode_segmentation::UnicodeSegmentation;
+    s.unicode_words()
+}
+#[cfg(not(feature = "unicode"))]
+fn get_iterator(s: &str) -> impl Iterator<Item = &str> {
+    s.split(|letter: char| !letter.is_ascii_alphanumeric())
+}
+
+fn transform<F, G>(
+    s: &str,
+    mut with_word: F,
+    mut boundary: G,
+    f: &mut fmt::Formatter,
+) -> fmt::Result
 where
-    F: Fn(&str, &mut String),
-    G: Fn(&mut String),
+    F: FnMut(&str, &mut fmt::Formatter) -> fmt::Result,
+    G: FnMut(&mut fmt::Formatter) -> fmt::Result,
 {
     /// Tracks the current 'mode' of the transformation algorithm as it scans
     /// the input string.
@@ -82,10 +105,9 @@ where
         Uppercase,
     }
 
-    let mut out = String::new();
     let mut first_word = true;
 
-    for word in s.unicode_words() {
+    for word in get_iterator(s) {
         let mut char_indices = word.char_indices().peekable();
         let mut init = 0;
         let mut mode = WordMode::Boundary;
@@ -114,9 +136,9 @@ where
                 // not uppercase and next is uppercase
                 if next == '_' || (next_mode == WordMode::Lowercase && next.is_uppercase()) {
                     if !first_word {
-                        boundary(&mut out);
+                        boundary(f)?;
                     }
-                    with_word(&word[init..next_i], &mut out);
+                    with_word(&word[init..next_i], f)?;
                     first_word = false;
                     init = next_i;
                     mode = WordMode::Boundary;
@@ -125,11 +147,11 @@ where
                 // is lowercase, word boundary before
                 } else if mode == WordMode::Uppercase && c.is_uppercase() && next.is_lowercase() {
                     if !first_word {
-                        boundary(&mut out);
+                        boundary(f)?;
                     } else {
                         first_word = false;
                     }
-                    with_word(&word[init..i], &mut out);
+                    with_word(&word[init..i], f)?;
                     init = i;
                     mode = WordMode::Boundary;
 
@@ -140,42 +162,48 @@ where
             } else {
                 // Collect trailing characters as a word
                 if !first_word {
-                    boundary(&mut out);
+                    boundary(f)?;
                 } else {
                     first_word = false;
                 }
-                with_word(&word[init..], &mut out);
+                with_word(&word[init..], f)?;
                 break;
             }
         }
     }
 
-    out
+    Ok(())
 }
 
-fn lowercase(s: &str, out: &mut String) {
+fn lowercase(s: &str, f: &mut fmt::Formatter) -> fmt::Result {
     let mut chars = s.chars().peekable();
     while let Some(c) = chars.next() {
         if c == 'Σ' && chars.peek().is_none() {
-            out.push('ς');
+            write!(f, "ς")?;
         } else {
-            out.extend(c.to_lowercase());
+            write!(f, "{}", c.to_lowercase())?;
         }
     }
+
+    Ok(())
 }
 
-fn uppercase(s: &str, out: &mut String) {
+fn uppercase(s: &str, f: &mut fmt::Formatter) -> fmt::Result {
     for c in s.chars() {
-        out.extend(c.to_uppercase())
+        write!(f, "{}", c.to_uppercase())?;
     }
+
+    Ok(())
 }
 
-fn capitalize(s: &str, out: &mut String) {
+fn capitalize(s: &str, f: &mut fmt::Formatter) -> fmt::Result {
     let mut char_indices = s.char_indices();
     if let Some((_, c)) = char_indices.next() {
-        out.extend(c.to_uppercase());
+        write!(f, "{}", c.to_uppercase())?;
         if let Some((i, _)) = char_indices.next() {
-            lowercase(&s[i..], out);
+            lowercase(&s[i..], f)?;
         }
     }
+
+    Ok(())
 }
diff --git a/src/lower_camel.rs b/src/lower_camel.rs
new file mode 100644
index 0000000..f1d6c94
--- /dev/null
+++ b/src/lower_camel.rs
@@ -0,0 +1,85 @@
+use std::fmt;
+
+use crate::{capitalize, lowercase, transform};
+
+/// This trait defines a lower camel case conversion.
+///
+/// In lowerCamelCase, word boundaries are indicated by capital letters,
+/// excepting the first word.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToLowerCamelCase;
+///
+/// let sentence = "It is we who built these palaces and cities.";
+/// assert_eq!(sentence.to_lower_camel_case(), "itIsWeWhoBuiltThesePalacesAndCities");
+/// ```
+pub trait ToLowerCamelCase: ToOwned {
+    /// Convert this type to lower camel case.
+    fn to_lower_camel_case(&self) -> Self::Owned;
+}
+
+impl ToLowerCamelCase for str {
+    fn to_lower_camel_case(&self) -> String {
+        AsLowerCamelCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a lower camel case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsLowerCamelCase;
+///
+/// let sentence = "It is we who built these palaces and cities.";
+/// assert_eq!(format!("{}", AsLowerCamelCase(sentence)), "itIsWeWhoBuiltThesePalacesAndCities");
+/// ```
+pub struct AsLowerCamelCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsLowerCamelCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let mut first = true;
+        transform(
+            self.0.as_ref(),
+            |s, f| {
+                if first {
+                    first = false;
+                    lowercase(s, f)
+                } else {
+                    capitalize(s, f)
+                }
+            },
+            |_| Ok(()),
+            f,
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToLowerCamelCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_lower_camel_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "camelCase");
+    t!(test2: "This is Human case." => "thisIsHumanCase");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "mixedUpCamelCaseWithSomeSpaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "mixedUpSnakeCaseWithSomeSpaces");
+    t!(test5: "kebab-case" => "kebabCase");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "shoutySnakeCase");
+    t!(test7: "snake_case" => "snakeCase");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "thisContainsAllKindsOfWordBoundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "xσxςBaffle");
+    t!(test10: "XMLHttpRequest" => "xmlHttpRequest");
+    // TODO unicode tests
+}
diff --git a/src/shouty_kebab.rs b/src/shouty_kebab.rs
index 0225471..e679978 100644
--- a/src/shouty_kebab.rs
+++ b/src/shouty_kebab.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{transform, uppercase};
 
 /// This trait defines a shouty kebab case conversion.
@@ -8,25 +10,43 @@ use crate::{transform, uppercase};
 /// ## Example:
 ///
 /// ```rust
-/// use heck::ShoutyKebabCase;
+/// use heck::ToShoutyKebabCase;
 ///
 /// let sentence = "We are going to inherit the earth.";
 /// assert_eq!(sentence.to_shouty_kebab_case(), "WE-ARE-GOING-TO-INHERIT-THE-EARTH");
 /// ```
-pub trait ShoutyKebabCase: ToOwned {
+pub trait ToShoutyKebabCase: ToOwned {
     /// Convert this type to shouty kebab case.
     fn to_shouty_kebab_case(&self) -> Self::Owned;
 }
 
-impl ShoutyKebabCase for str {
+impl ToShoutyKebabCase for str {
     fn to_shouty_kebab_case(&self) -> Self::Owned {
-        transform(self, uppercase, |s| s.push('-'))
+        AsShoutyKebabCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a kebab case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsShoutyKebabCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(format!("{}", AsShoutyKebabCase(sentence)), "WE-ARE-GOING-TO-INHERIT-THE-EARTH");
+/// ```
+pub struct AsShoutyKebabCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsShoutyKebabCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), uppercase, |f| write!(f, "-"), f)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::ShoutyKebabCase;
+    use super::ToShoutyKebabCase;
 
     macro_rules! t {
         ($t:ident : $s1:expr => $s2:expr) => {
@@ -45,6 +65,7 @@ mod tests {
     t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY-SNAKE-CASE");
     t!(test7: "snake_case" => "SNAKE-CASE");
     t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS-CONTAINS-ALL-KINDS-OF-WORD-BOUNDARIES");
+    #[cfg(feature = "unicode")]
     t!(test9: "XΣXΣ baffle" => "XΣXΣ-BAFFLE");
     t!(test10: "XMLHttpRequest" => "XML-HTTP-REQUEST");
     t!(test11: "SHOUTY-KEBAB-CASE" => "SHOUTY-KEBAB-CASE");
diff --git a/src/shouty_snake.rs b/src/shouty_snake.rs
index 8f4289a..d504375 100644
--- a/src/shouty_snake.rs
+++ b/src/shouty_snake.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{transform, uppercase};
 
 /// This trait defines a shouty snake case conversion.
@@ -8,39 +10,57 @@ use crate::{transform, uppercase};
 /// ## Example:
 ///
 /// ```rust
-/// use heck::ShoutySnakeCase;
-///     
+/// use heck::ToShoutySnakeCase;
+///
 /// let sentence = "That world is growing in this minute.";
 /// assert_eq!(sentence.to_shouty_snake_case(), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
 /// ```
-pub trait ShoutySnakeCase: ToOwned {
+pub trait ToShoutySnakeCase: ToOwned {
     /// Convert this type to shouty snake case.
     fn to_shouty_snake_case(&self) -> Self::Owned;
 }
 
-/// Oh heck, ShoutySnekCase is an alias for ShoutySnakeCase. See ShoutySnakeCase
-/// for more documentation.
-pub trait ShoutySnekCase: ToOwned {
+/// Oh heck, ToShoutySnekCase is an alias for ToShoutySnakeCase. See
+/// ToShoutySnakeCase for more documentation.
+pub trait ToShoutySnekCase: ToOwned {
     /// CONVERT THIS TYPE TO SNEK CASE.
     #[allow(non_snake_case)]
     fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned;
 }
 
-impl<T: ?Sized + ShoutySnakeCase> ShoutySnekCase for T {
+impl<T: ?Sized + ToShoutySnakeCase> ToShoutySnekCase for T {
     fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned {
         self.to_shouty_snake_case()
     }
 }
 
-impl ShoutySnakeCase for str {
+impl ToShoutySnakeCase for str {
     fn to_shouty_snake_case(&self) -> Self::Owned {
-        transform(self, uppercase, |s| s.push('_'))
+        AsShoutySnakeCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a shouty snake  case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsShoutySnakeCase;
+///
+/// let sentence = "That world is growing in this minute.";
+/// assert_eq!(format!("{}", AsShoutySnakeCase(sentence)), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
+/// ```
+pub struct AsShoutySnakeCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsShoutySnakeCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), uppercase, |f| write!(f, "_"), f)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::ShoutySnakeCase;
+    use super::ToShoutySnakeCase;
 
     macro_rules! t {
         ($t:ident : $s1:expr => $s2:expr) => {
@@ -59,6 +79,7 @@ mod tests {
     t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY_SNAKE_CASE");
     t!(test7: "snake_case" => "SNAKE_CASE");
     t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS_CONTAINS_ALL_KINDS_OF_WORD_BOUNDARIES");
+    #[cfg(feature = "unicode")]
     t!(test9: "XΣXΣ baffle" => "XΣXΣ_BAFFLE");
     t!(test10: "XMLHttpRequest" => "XML_HTTP_REQUEST");
 }
diff --git a/src/snake.rs b/src/snake.rs
index c1ad376..127a864 100644
--- a/src/snake.rs
+++ b/src/snake.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{lowercase, transform};
 
 /// This trait defines a snake case conversion.
@@ -7,38 +9,56 @@ use crate::{lowercase, transform};
 /// ## Example:
 ///
 /// ```rust
-/// use heck::SnakeCase;
+/// use heck::ToSnakeCase;
 ///
 /// let sentence = "We carry a new world here, in our hearts.";
 /// assert_eq!(sentence.to_snake_case(), "we_carry_a_new_world_here_in_our_hearts");
 /// ```
-pub trait SnakeCase: ToOwned {
+pub trait ToSnakeCase: ToOwned {
     /// Convert this type to snake case.
     fn to_snake_case(&self) -> Self::Owned;
 }
 
-/// Oh heck, SnekCase is an alias for SnakeCase. See SnakeCase for
+/// Oh heck, SnekCase is an alias for ToSnakeCase. See ToSnakeCase for
 /// more documentation.
-pub trait SnekCase: ToOwned {
+pub trait ToSnekCase: ToOwned {
     /// Convert this type to snek case.
     fn to_snek_case(&self) -> Self::Owned;
 }
 
-impl<T: ?Sized + SnakeCase> SnekCase for T {
+impl<T: ?Sized + ToSnakeCase> ToSnekCase for T {
     fn to_snek_case(&self) -> Self::Owned {
         self.to_snake_case()
     }
 }
 
-impl SnakeCase for str {
+impl ToSnakeCase for str {
     fn to_snake_case(&self) -> String {
-        transform(self, lowercase, |s| s.push('_'))
+        AsSnakeCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a snake case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsSnakeCase;
+///
+/// let sentence = "We carry a new world here, in our hearts.";
+/// assert_eq!(format!("{}", AsSnakeCase(sentence)), "we_carry_a_new_world_here_in_our_hearts");
+/// ```
+pub struct AsSnakeCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsSnakeCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), lowercase, |f| write!(f, "_"), f)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::SnakeCase;
+    use super::ToSnakeCase;
 
     macro_rules! t {
         ($t:ident : $s1:expr => $s2:expr) => {
@@ -57,6 +77,7 @@ mod tests {
     t!(test6: "SHOUTY_SNAKE_CASE" => "shouty_snake_case");
     t!(test7: "snake_case" => "snake_case");
     t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "this_contains_all_kinds_of_word_boundaries");
+    #[cfg(feature = "unicode")]
     t!(test9: "XΣXΣ baffle" => "xσxς_baffle");
     t!(test10: "XMLHttpRequest" => "xml_http_request");
     t!(test11: "FIELD_NAME11" => "field_name11");
diff --git a/src/title.rs b/src/title.rs
index 015a9fa..fdf175b 100644
--- a/src/title.rs
+++ b/src/title.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use crate::{capitalize, transform};
 
 /// This trait defines a title case conversion.
@@ -8,25 +10,43 @@ use crate::{capitalize, transform};
 /// ## Example:
 ///
 /// ```rust
-/// use heck::TitleCase;
+/// use heck::ToTitleCase;
 ///
 /// let sentence = "We have always lived in slums and holes in the wall.";
 /// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall");
 /// ```
-pub trait TitleCase: ToOwned {
+pub trait ToTitleCase: ToOwned {
     /// Convert this type to title case.
     fn to_title_case(&self) -> Self::Owned;
 }
 
-impl TitleCase for str {
+impl ToTitleCase for str {
     fn to_title_case(&self) -> String {
-        transform(self, capitalize, |s| s.push(' '))
+        AsTitleCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a title case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsTitleCase;
+///
+/// let sentence = "We have always lived in slums and holes in the wall.";
+/// assert_eq!(format!("{}", AsTitleCase(sentence)), "We Have Always Lived In Slums And Holes In The Wall");
+/// ```
+pub struct AsTitleCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsTitleCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |f| write!(f, " "), f)
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use super::TitleCase;
+    use super::ToTitleCase;
 
     macro_rules! t {
         ($t:ident : $s1:expr => $s2:expr) => {
@@ -45,6 +65,7 @@ mod tests {
     t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case");
     t!(test7: "snake_case" => "Snake Case");
     t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries");
+    #[cfg(feature = "unicode")]
     t!(test9: "XΣXΣ baffle" => "Xσxς Baffle");
     t!(test10: "XMLHttpRequest" => "Xml Http Request");
 }
diff --git a/src/train.rs b/src/train.rs
new file mode 100644
index 0000000..04dd6a9
--- /dev/null
+++ b/src/train.rs
@@ -0,0 +1,85 @@
+use std::fmt;
+
+use crate::{capitalize, transform};
+
+/// This trait defines a train case conversion.
+///
+/// In Train-Case, word boundaries are indicated by hyphens and words start
+/// with Capital Letters.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToTrainCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(sentence.to_train_case(), "We-Are-Going-To-Inherit-The-Earth");
+/// ```
+pub trait ToTrainCase: ToOwned {
+    /// Convert this type to Train-Case.
+    fn to_train_case(&self) -> Self::Owned;
+}
+
+impl ToTrainCase for str {
+    fn to_train_case(&self) -> Self::Owned {
+        AsTrainCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a train case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsTrainCase;
+///
+/// let sentence = "We are going to inherit the earth.";
+/// assert_eq!(format!("{}", AsTrainCase(sentence)), "We-Are-Going-To-Inherit-The-Earth");
+/// ```
+pub struct AsTrainCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsTrainCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |f| write!(f, "-"), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToTrainCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_train_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "Camel-Case");
+    t!(test2: "This is Human case." => "This-Is-Human-Case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed-Up-Camel-Case-With-Some-Spaces");
+    t!(test4: "mixed_up_ snake_case with some _spaces" => "Mixed-Up-Snake-Case-With-Some-Spaces");
+    t!(test5: "kebab-case" => "Kebab-Case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty-Snake-Case");
+    t!(test7: "snake_case" => "Snake-Case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This-Contains-All-Kinds-Of-Word-Boundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "Xσxς-Baffle");
+    t!(test10: "XMLHttpRequest" => "Xml-Http-Request");
+    t!(test11: "FIELD_NAME11" => "Field-Name11");
+    t!(test12: "99BOTTLES" => "99bottles");
+    t!(test13: "FieldNamE11" => "Field-Nam-E11");
+    t!(test14: "abc123def456" => "Abc123def456");
+    t!(test16: "abc123DEF456" => "Abc123-Def456");
+    t!(test17: "abc123Def456" => "Abc123-Def456");
+    t!(test18: "abc123DEf456" => "Abc123-D-Ef456");
+    t!(test19: "ABC123def456" => "Abc123def456");
+    t!(test20: "ABC123DEF456" => "Abc123def456");
+    t!(test21: "ABC123Def456" => "Abc123-Def456");
+    t!(test22: "ABC123DEf456" => "Abc123d-Ef456");
+    t!(test23: "ABC123dEEf456FOO" => "Abc123d-E-Ef456-Foo");
+    t!(test24: "abcDEF" => "Abc-Def");
+    t!(test25: "ABcDE" => "A-Bc-De");
+}
diff --git a/src/upper_camel.rs b/src/upper_camel.rs
new file mode 100644
index 0000000..70bf4ac
--- /dev/null
+++ b/src/upper_camel.rs
@@ -0,0 +1,84 @@
+use std::fmt;
+
+use crate::{capitalize, transform};
+
+/// This trait defines an upper camel case conversion.
+///
+/// In UpperCamelCase, word boundaries are indicated by capital letters,
+/// including the first word.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToUpperCamelCase;
+///
+/// let sentence = "We are not in the least afraid of ruins.";
+/// assert_eq!(sentence.to_upper_camel_case(), "WeAreNotInTheLeastAfraidOfRuins");
+/// ```
+pub trait ToUpperCamelCase: ToOwned {
+    /// Convert this type to upper camel case.
+    fn to_upper_camel_case(&self) -> Self::Owned;
+}
+
+impl ToUpperCamelCase for str {
+    fn to_upper_camel_case(&self) -> String {
+        AsUpperCamelCase(self).to_string()
+    }
+}
+
+/// ToPascalCase is an alias for ToUpperCamelCase. See ToUpperCamelCase for more
+/// documentation.
+pub trait ToPascalCase: ToOwned {
+    /// Convert this type to upper camel case.
+    fn to_pascal_case(&self) -> Self::Owned;
+}
+
+impl<T: ?Sized + ToUpperCamelCase> ToPascalCase for T {
+    fn to_pascal_case(&self) -> Self::Owned {
+        self.to_upper_camel_case()
+    }
+}
+
+/// This wrapper performs a upper camel case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsUpperCamelCase;
+///
+/// let sentence = "We are not in the least afraid of ruins.";
+/// assert_eq!(format!("{}", AsUpperCamelCase(sentence)), "WeAreNotInTheLeastAfraidOfRuins");
+/// ```
+pub struct AsUpperCamelCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsUpperCamelCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |_| Ok(()), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToUpperCamelCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_upper_camel_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "CamelCase");
+    t!(test2: "This is Human case." => "ThisIsHumanCase");
+    t!(test3: "MixedUP_CamelCase, with some Spaces" => "MixedUpCamelCaseWithSomeSpaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "MixedUpSnakeCaseWithSomeSpaces");
+    t!(test5: "kebab-case" => "KebabCase");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "ShoutySnakeCase");
+    t!(test7: "snake_case" => "SnakeCase");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "ThisContainsAllKindsOfWordBoundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baffle" => "XσxςBaffle");
+    t!(test10: "XMLHttpRequest" => "XmlHttpRequest");
+}