/*
    is parametrized: no
*/

#ifndef GUF_ALLOC_H
#define GUF_ALLOC_H
#include "guf_common.h"
#include "guf_assert.h"

// A custom allocator interface as described in https://nullprogram.com/blog/2023/12/17/ (last-retrieved 2025-01-25)
typedef struct guf_allocator {
    void *(*alloc)(ptrdiff_t size, void *ctx);
    void *(*realloc)(void *ptr, ptrdiff_t old_size, ptrdiff_t new_size, void *ctx);
    void (*free)(void *ptr, ptrdiff_t size, void *ctx);
    void *ctx; 
} guf_allocator;

// typedef enum guf_alloc_fn_type {
//     GUF_ALLOC_FN_TYPE_ALLOC, 
//     GUF_ALLOC_FN_TYPE_REALLOC,
//     GUF_ALLOC_FN_TYPE_FREE,
// } guf_alloc_fn_type;

/*
    GUF_ALLOC_MAX_BYTES:    Largest number of bytes an allocated buffer of elements of TYPE can have.
    GUF_ALLOC_MAX_CAPACITY: Largest number of elements an allocated buffer of elements of TYPE can have.
*/
#define GUF_ALLOC_MAX_BYTES(TYPE)    ( PTRDIFF_MAX - ( PTRDIFF_MAX % sizeof(TYPE) ) )
#define GUF_ALLOC_MAX_CAPACITY(TYPE) ( GUF_ALLOC_MAX_BYTES(TYPE) / sizeof(TYPE) )

#endif