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-rw-r--r--include/pybind11/buffer_info.h146
1 files changed, 104 insertions, 42 deletions
diff --git a/include/pybind11/buffer_info.h b/include/pybind11/buffer_info.h
index d803004a..b99ee8be 100644
--- a/include/pybind11/buffer_info.h
+++ b/include/pybind11/buffer_info.h
@@ -19,9 +19,11 @@ PYBIND11_NAMESPACE_BEGIN(detail)
inline std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
auto ndim = shape.size();
std::vector<ssize_t> strides(ndim, itemsize);
- if (ndim > 0)
- for (size_t i = ndim - 1; i > 0; --i)
+ if (ndim > 0) {
+ for (size_t i = ndim - 1; i > 0; --i) {
strides[i - 1] = strides[i] * shape[i];
+ }
+ }
return strides;
}
@@ -29,11 +31,15 @@ inline std::vector<ssize_t> c_strides(const std::vector<ssize_t> &shape, ssize_t
inline std::vector<ssize_t> f_strides(const std::vector<ssize_t> &shape, ssize_t itemsize) {
auto ndim = shape.size();
std::vector<ssize_t> strides(ndim, itemsize);
- for (size_t i = 1; i < ndim; ++i)
+ for (size_t i = 1; i < ndim; ++i) {
strides[i] = strides[i - 1] * shape[i - 1];
+ }
return strides;
}
+template <typename T, typename SFINAE = void>
+struct compare_buffer_info;
+
PYBIND11_NAMESPACE_END(detail)
/// Information record describing a Python buffer object
@@ -41,61 +47,89 @@ struct buffer_info {
void *ptr = nullptr; // Pointer to the underlying storage
ssize_t itemsize = 0; // Size of individual items in bytes
ssize_t size = 0; // Total number of entries
- std::string format; // For homogeneous buffers, this should be set to format_descriptor<T>::format()
+ std::string format; // For homogeneous buffers, this should be set to
+ // format_descriptor<T>::format()
ssize_t ndim = 0; // Number of dimensions
std::vector<ssize_t> shape; // Shape of the tensor (1 entry per dimension)
- std::vector<ssize_t> strides; // Number of bytes between adjacent entries (for each per dimension)
+ std::vector<ssize_t> strides; // Number of bytes between adjacent entries
+ // (for each per dimension)
bool readonly = false; // flag to indicate if the underlying storage may be written to
buffer_info() = default;
- buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
- detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in, bool readonly=false)
- : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
- shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
- if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size())
+ buffer_info(void *ptr,
+ ssize_t itemsize,
+ const std::string &format,
+ ssize_t ndim,
+ detail::any_container<ssize_t> shape_in,
+ detail::any_container<ssize_t> strides_in,
+ bool readonly = false)
+ : ptr(ptr), itemsize(itemsize), size(1), format(format), ndim(ndim),
+ shape(std::move(shape_in)), strides(std::move(strides_in)), readonly(readonly) {
+ if (ndim != (ssize_t) shape.size() || ndim != (ssize_t) strides.size()) {
pybind11_fail("buffer_info: ndim doesn't match shape and/or strides length");
- for (size_t i = 0; i < (size_t) ndim; ++i)
+ }
+ for (size_t i = 0; i < (size_t) ndim; ++i) {
size *= shape[i];
+ }
}
template <typename T>
- buffer_info(T *ptr, detail::any_container<ssize_t> shape_in, detail::any_container<ssize_t> strides_in, bool readonly=false)
- : buffer_info(private_ctr_tag(), ptr, sizeof(T), format_descriptor<T>::format(), static_cast<ssize_t>(shape_in->size()), std::move(shape_in), std::move(strides_in), readonly) { }
-
- buffer_info(void *ptr, ssize_t itemsize, const std::string &format, ssize_t size, bool readonly=false)
- : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}, readonly) { }
+ buffer_info(T *ptr,
+ detail::any_container<ssize_t> shape_in,
+ detail::any_container<ssize_t> strides_in,
+ bool readonly = false)
+ : buffer_info(private_ctr_tag(),
+ ptr,
+ sizeof(T),
+ format_descriptor<T>::format(),
+ static_cast<ssize_t>(shape_in->size()),
+ std::move(shape_in),
+ std::move(strides_in),
+ readonly) {}
+
+ buffer_info(void *ptr,
+ ssize_t itemsize,
+ const std::string &format,
+ ssize_t size,
+ bool readonly = false)
+ : buffer_info(ptr, itemsize, format, 1, {size}, {itemsize}, readonly) {}
template <typename T>
- buffer_info(T *ptr, ssize_t size, bool readonly=false)
- : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size, readonly) { }
+ buffer_info(T *ptr, ssize_t size, bool readonly = false)
+ : buffer_info(ptr, sizeof(T), format_descriptor<T>::format(), size, readonly) {}
template <typename T>
- buffer_info(const T *ptr, ssize_t size, bool readonly=true)
- : buffer_info(const_cast<T*>(ptr), sizeof(T), format_descriptor<T>::format(), size, readonly) { }
+ buffer_info(const T *ptr, ssize_t size, bool readonly = true)
+ : buffer_info(
+ const_cast<T *>(ptr), sizeof(T), format_descriptor<T>::format(), size, readonly) {}
explicit buffer_info(Py_buffer *view, bool ownview = true)
- : buffer_info(view->buf, view->itemsize, view->format, view->ndim,
+ : buffer_info(
+ view->buf,
+ view->itemsize,
+ view->format,
+ view->ndim,
{view->shape, view->shape + view->ndim},
/* Though buffer::request() requests PyBUF_STRIDES, ctypes objects
* ignore this flag and return a view with NULL strides.
* When strides are NULL, build them manually. */
view->strides
- ? std::vector<ssize_t>(view->strides, view->strides + view->ndim)
- : detail::c_strides({view->shape, view->shape + view->ndim}, view->itemsize),
- view->readonly) {
+ ? std::vector<ssize_t>(view->strides, view->strides + view->ndim)
+ : detail::c_strides({view->shape, view->shape + view->ndim}, view->itemsize),
+ (view->readonly != 0)) {
+ // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
this->m_view = view;
+ // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
this->ownview = ownview;
}
buffer_info(const buffer_info &) = delete;
- buffer_info& operator=(const buffer_info &) = delete;
+ buffer_info &operator=(const buffer_info &) = delete;
- buffer_info(buffer_info &&other) {
- (*this) = std::move(other);
- }
+ buffer_info(buffer_info &&other) noexcept { (*this) = std::move(other); }
- buffer_info& operator=(buffer_info &&rhs) {
+ buffer_info &operator=(buffer_info &&rhs) noexcept {
ptr = rhs.ptr;
itemsize = rhs.itemsize;
size = rhs.size;
@@ -110,17 +144,39 @@ struct buffer_info {
}
~buffer_info() {
- if (m_view && ownview) { PyBuffer_Release(m_view); delete m_view; }
+ if (m_view && ownview) {
+ PyBuffer_Release(m_view);
+ delete m_view;
+ }
}
Py_buffer *view() const { return m_view; }
Py_buffer *&view() { return m_view; }
-private:
- struct private_ctr_tag { };
- buffer_info(private_ctr_tag, void *ptr, ssize_t itemsize, const std::string &format, ssize_t ndim,
- detail::any_container<ssize_t> &&shape_in, detail::any_container<ssize_t> &&strides_in, bool readonly)
- : buffer_info(ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in), readonly) { }
+ /* True if the buffer item type is equivalent to `T`. */
+ // To define "equivalent" by example:
+ // `buffer_info::item_type_is_equivalent_to<int>(b)` and
+ // `buffer_info::item_type_is_equivalent_to<long>(b)` may both be true
+ // on some platforms, but `int` and `unsigned` will never be equivalent.
+ // For the ground truth, please inspect `detail::compare_buffer_info<>`.
+ template <typename T>
+ bool item_type_is_equivalent_to() const {
+ return detail::compare_buffer_info<T>::compare(*this);
+ }
+
+private:
+ struct private_ctr_tag {};
+
+ buffer_info(private_ctr_tag,
+ void *ptr,
+ ssize_t itemsize,
+ const std::string &format,
+ ssize_t ndim,
+ detail::any_container<ssize_t> &&shape_in,
+ detail::any_container<ssize_t> &&strides_in,
+ bool readonly)
+ : buffer_info(
+ ptr, itemsize, format, ndim, std::move(shape_in), std::move(strides_in), readonly) {}
Py_buffer *m_view = nullptr;
bool ownview = false;
@@ -128,17 +184,23 @@ private:
PYBIND11_NAMESPACE_BEGIN(detail)
-template <typename T, typename SFINAE = void> struct compare_buffer_info {
- static bool compare(const buffer_info& b) {
+template <typename T, typename SFINAE>
+struct compare_buffer_info {
+ static bool compare(const buffer_info &b) {
+ // NOLINTNEXTLINE(bugprone-sizeof-expression) Needed for `PyObject *`
return b.format == format_descriptor<T>::format() && b.itemsize == (ssize_t) sizeof(T);
}
};
-template <typename T> struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
- static bool compare(const buffer_info& b) {
- return (size_t) b.itemsize == sizeof(T) && (b.format == format_descriptor<T>::value ||
- ((sizeof(T) == sizeof(long)) && b.format == (std::is_unsigned<T>::value ? "L" : "l")) ||
- ((sizeof(T) == sizeof(size_t)) && b.format == (std::is_unsigned<T>::value ? "N" : "n")));
+template <typename T>
+struct compare_buffer_info<T, detail::enable_if_t<std::is_integral<T>::value>> {
+ static bool compare(const buffer_info &b) {
+ return (size_t) b.itemsize == sizeof(T)
+ && (b.format == format_descriptor<T>::value
+ || ((sizeof(T) == sizeof(long))
+ && b.format == (std::is_unsigned<T>::value ? "L" : "l"))
+ || ((sizeof(T) == sizeof(size_t))
+ && b.format == (std::is_unsigned<T>::value ? "N" : "n")));
}
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-20 12:41:26 +0000