Type Alias GLFWallocatefun Copy item path

@brief The function pointer type for memory allocation callbacks.

This is the function pointer type for memory allocation callbacks. A memory allocation callback function has the following signature: @code void* function_name(size_t size, void* user) @endcode

This function must return either a memory block at least size bytes long, or NULL if allocation failed. Note that not all parts of GLFW handle allocation failures gracefully yet.

This function must support being called during @ref glfwInit but before the library is flagged as initialized, as well as during @ref glfwTerminate after the library is no longer flagged as initialized.

Any memory allocated via this function will be deallocated via the same allocator during library termination or earlier.

Any memory allocated via this function must be suitably aligned for any object type. If you are using C99 or earlier, this alignment is platform-dependent but will be the same as what malloc provides. If you are using C11 or later, this is the value of alignof(max_align_t).

The size will always be greater than zero. Allocations of size zero are filtered out before reaching the custom allocator.

If this function returns NULL, GLFW will emit @ref GLFW_OUT_OF_MEMORY.

This function must not call any GLFW function.

@param[in] size The minimum size, in bytes, of the memory block. @param[in] user The user-defined pointer from the allocator. @return The address of the newly allocated memory block, or NULL if an error occurred.

@pointer_lifetime The returned memory block must be valid at least until it is deallocated.

@reentrancy This function should not call any GLFW function.

@thread_safety This function must support being called from any thread that calls GLFW functions.

@sa @ref init_allocator @sa @ref GLFWallocator

@since Added in version 3.4.

@ingroup init