(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_realloc

Change the size of allocated memory.

Header File

Syntax

void * SDL_realloc(void *mem, size_t size);

Function Parameters

void *	mem	a pointer to allocated memory to reallocate, or NULL.
size_t	size	the new size of the memory.

Return Value

(void *) Returns a pointer to the newly allocated memory, or NULL if allocation failed.

Remarks

The memory returned by this function must be freed with SDL_free().

If size is 0, it will be set to 1. Note that this is unlike some other C runtime realloc implementations, which may treat realloc(mem, 0) the same way as free(mem).

If mem is NULL, the behavior of this function is equivalent to SDL_malloc(). Otherwise, the function can have one of three possible outcomes:

If it returns the same pointer as mem, it means that mem was resized in place without freeing.
If it returns a different non-NULL pointer, it means that mem was freed and cannot be dereferenced anymore.
If it returns NULL (indicating failure), then mem will remain valid and must still be freed with SDL_free().

Thread Safety

It is safe to call this function from any thread.

Version

This function is available since SDL 3.1.3.