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

SDL_stack_alloc

Allocate memory on the stack (maybe).

Header File

Syntax

#define SDL_stack_alloc(type, count)    (type*)alloca(sizeof(type)*(count))

Macro Parameters

type	the datatype of the memory to allocate.
count	the number of `type` objects to allocate.

Return Value

Returns newly-allocated memory, or NULL on failure.

Remarks

If SDL knows how to access alloca() on the current platform, it will use it to stack-allocate memory here. If it doesn't, it will use SDL_malloc() to heap-allocate memory.

Since this might not be stack memory at all, it's important that you check the returned pointer for NULL, and that you call SDL_stack_free on the memory when done with it. Since this might be stack memory, it's important that you don't allocate large amounts of it, or allocate in a loop without returning from the function, so the stack doesn't overflow.

Thread Safety

It is safe to call this macro from any thread.

Version

This macro is available since SDL 3.1.3.