diff options
author | Jacques Lucke <jacques@blender.org> | 2020-12-16 17:59:58 +0300 |
---|---|---|
committer | Jacques Lucke <jacques@blender.org> | 2020-12-16 18:00:17 +0300 |
commit | 4463087223983c40a6d67beab0513fba7cdb7538 (patch) | |
tree | f067cffc02bfb39fc4573615b3517b8e4cdcac65 /source/blender/blenlib/BLI_span.hh | |
parent | 684c771263db1a5a7dbf65cde97e672d94b57839 (diff) |
BLI: remove implicit casts between some span types
Casting pointers from one type to another does change the
value of the pointer in some cases. Therefore, casting a span
that contains pointers of one type to a span that contains
pointers of another type, is not generally safe. In practice, this
issue mainly comes up when dealing with classes that have a
vtable.
There are some special cases that are still allowed. For example,
adding const to the pointer does not change the address.
Also, casting to a void pointer is fine.
In cases where implicit conversion is disabled, but one is sure
that the cast is valid, an explicit call of `span.cast<NewType>()`
can be used.
Diffstat (limited to 'source/blender/blenlib/BLI_span.hh')
-rw-r--r-- | source/blender/blenlib/BLI_span.hh | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/source/blender/blenlib/BLI_span.hh b/source/blender/blenlib/BLI_span.hh index 3f410efe908..8011b2f9abc 100644 --- a/source/blender/blenlib/BLI_span.hh +++ b/source/blender/blenlib/BLI_span.hh @@ -100,7 +100,7 @@ template<typename T> class Span { BLI_assert(size >= 0); } - template<typename U, typename std::enable_if_t<is_convertible_pointer_v<U, T>> * = nullptr> + template<typename U, typename std::enable_if_t<is_span_convertible_pointer_v<U, T>> * = nullptr> constexpr Span(const U *start, int64_t size) : data_(static_cast<const T *>(start)), size_(size) { BLI_assert(size >= 0); @@ -135,7 +135,8 @@ template<typename T> class Span { * Support implicit conversions like the ones below: * Span<T *> -> Span<const T *> */ - template<typename U, typename std::enable_if_t<is_convertible_pointer_v<U, T>> * = nullptr> + + template<typename U, typename std::enable_if_t<is_span_convertible_pointer_v<U, T>> * = nullptr> constexpr Span(Span<U> array) : data_(static_cast<const T *>(array.data())), size_(array.size()) { } |