Function SDL_IOFromConstMem

pub unsafe extern "C" fn SDL_IOFromConstMem(
    mem: *const c_void,
    size: usize,
) -> *mut SDL_IOStream

Available on crate feature dep_sdl3 only.

Use this function to prepare a read-only memory buffer for use with SDL_IOStream.

This function sets up an SDL_IOStream struct based on a memory area of a certain size. It assumes the memory area is not writable.

Attempting to write to this SDL_IOStream stream will report an error without writing to the memory buffer.

This memory buffer is not copied by the SDL_IOStream; the pointer you provide must remain valid until you close the stream. Closing the stream will not free the original buffer.

If you need to write to a memory buffer, you should use SDL_IOFromMem() with a writable buffer of memory instead.

The following properties will be set at creation time by SDL:

• SDL_PROP_IOSTREAM_MEMORY_POINTER: this will be the mem parameter that was passed to this function.
• SDL_PROP_IOSTREAM_MEMORY_SIZE_NUMBER: this will be the size parameter that was passed to this function.

Parameters

• mem: a pointer to a read-only buffer to feed an SDL_IOStream stream.
• size: the buffer size, in bytes.

Return value

Returns a pointer to a new SDL_IOStream structure or NULL on failure; call SDL_GetError() for more information.

Thread safety

It is safe to call this function from any thread.

Availability

This function is available since SDL 3.2.0.

See also

• SDL_IOFromMem
• SDL_CloseIO
• SDL_ReadIO
• SDL_SeekIO
• SDL_TellIO