Provided by: libsdl3-doc_3.2.26+ds-2_all 

NAME
SDL_MessageBoxButtonFlags - SDL_MessageBoxButtonData flags.
SYNOPSIS
#include <SDL3/SDL_messagebox.h>
typedef Uint32 SDL_MessageBoxButtonFlags;
#define SDL_MESSAGEBOX_BUTTON_RETURNKEY_DEFAULT 0x00000001u /**< Marks the default button when return is hit */
#define SDL_MESSAGEBOX_BUTTON_ESCAPEKEY_DEFAULT 0x00000002u /**< Marks the default button when escape is hit */
AVAILABILITY
This datatype is available since SDL 3.2.0.
Simple Directmedia Layer SDL 3.2.26 SDL_MessageBoxButtonFlags(3type)