diff options
Diffstat (limited to 'source/blender/blenlib/BLI_memory_utils.hh')
| -rw-r--r-- | source/blender/blenlib/BLI_memory_utils.hh | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/source/blender/blenlib/BLI_memory_utils.hh b/source/blender/blenlib/BLI_memory_utils.hh index 49076bb1aae..b3b6855089e 100644 --- a/source/blender/blenlib/BLI_memory_utils.hh +++ b/source/blender/blenlib/BLI_memory_utils.hh @@ -428,6 +428,25 @@ inline constexpr bool is_convertible_pointer_v = std::is_convertible_v<From, To> &&std::is_pointer_v<From> &&std::is_pointer_v<To>; /** + * Helper variable that checks if a Span<From> can be converted to Span<To> safely, whereby From + * and To are pointers. Adding const and casting to a void pointer is allowed. + * Casting up and down a class hierarchy generally is not allowed, because this might change the + * pointer under some circumstances. + */ +template<typename From, typename To> +inline constexpr bool is_span_convertible_pointer_v = + /* Make sure we are working with pointers. */ + std::is_pointer_v<From> &&std::is_pointer_v<To> && + (/* No casting is necessary when both types are the same. */ + std::is_same_v<From, To> || + /* Allow adding const to the underlying type. */ + std::is_same_v<const std::remove_pointer_t<From>, std::remove_pointer_t<To>> || + /* Allow casting non-const pointers to void pointers. */ + (!std::is_const_v<std::remove_pointer_t<From>> && std::is_same_v<To, void *>) || + /* Allow casting any pointer to const void pointers. */ + std::is_same_v<To, const void *>); + +/** * Inline buffers for small-object-optimization should be disable by default. Otherwise we might * get large unexpected allocations on the stack. */ |