1 files changed, 73 insertions, 0 deletions
diff --git a/pw_minimal_cpp_stdlib/public/pw_minimal_cpp_stdlib/internal/string.h b/pw_minimal_cpp_stdlib/public/pw_minimal_cpp_stdlib/internal/string.h
new file mode 100644
index 000000000..a89125117
--- /dev/null
+++ b/pw_minimal_cpp_stdlib/public/pw_minimal_cpp_stdlib/internal/string.h
@@ -0,0 +1,73 @@
+// Copyright 2023 The Pigweed Authors
+//
+// 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
+//
+//     https://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.
+#pragma once
+
+#include "pw_polyfill/standard_library/namespace.h"
+
+_PW_POLYFILL_BEGIN_NAMESPACE_STD
+
+// NOT IMPLEMENTED: Some functions and overloads are missing.
+template <typename T>
+class char_traits {
+ public:
+  static constexpr void assign(T& dest, const T& source) noexcept {
+    dest = source;
+  }
+
+  static constexpr T* assign(T* dest, decltype(sizeof(0)) count, T value) {
+    for (decltype(sizeof(0)) i = 0; i < count; ++i) {
+      dest[i] = value;
+    }
+    return dest;
+  }
+
+  static constexpr bool eq(T lhs, T rhs) noexcept { return lhs == rhs; }
+
+  static constexpr bool lt(T lhs, T rhs) noexcept { return lhs < rhs; }
+
+  static constexpr T* move(T* dest,
+                           const T* source,
+                           decltype(sizeof(0)) count) {
+    if (dest < source) {
+      copy(dest, source, count);
+    } else if (source < dest) {
+      for (decltype(sizeof(0)) i = count; i != 0; --i) {
+        assign(dest[i - 1], source[i - 1]);
+      }
+    }
+    return dest;
+  }
+
+  static constexpr T* copy(T* dest,
+                           const T* source,
+                           decltype(sizeof(0)) count) {
+    for (decltype(sizeof(0)) i = 0; i < count; ++i) {
+      char_traits<T>::assign(dest[i], source[i]);
+    }
+    return dest;
+  }
+
+  static constexpr int compare(const T* lhs,
+                               const T* rhs,
+                               decltype(sizeof(0)) count) {
+    for (decltype(sizeof(0)) i = 0; i < count; ++i) {
+      if (!eq(lhs[i], rhs[i])) {
+        return lt(lhs[i], rhs[i]) ? -1 : 1;
+      }
+    }
+    return 0;
+  }
+};
+
+_PW_POLYFILL_END_NAMESPACE_STD