SDL_bsearch_r - Man Page

Perform a binary search on a previously sorted array, passing a userdata pointer to the compare function.

Header File

Defined in SDL3/SDL_stdinc.h

Synopsis

#include "SDL3/SDL.h"

void * SDL_bsearch_r(const void *key, const void *base, size_t nmemb, size_t size, SDL_CompareCallback_r compare, void *userdata);

Description

For example:

typedef enum {
    sort_increasing,
    sort_decreasing,
} sort_method;

typedef struct {
    int key;
    const char *string;
} data;

int SDLCALL compare(const void *userdata, const void *a, const void *b)
{
    sort_method method = (sort_method)(uintptr_t)userdata;
    const data *A = (const data *)a;
    const data *B = (const data *)b;

    if (A->key < B->key) {
        return (method == sort_increasing) ? -1 : 1;
    } else if (B->key < A->key) {
        return (method == sort_increasing) ? 1 : -1;
    } else {
        return 0;
    }
}

data values[] = {
    { 1, "first" }, { 2, "second" }, { 3, "third" }
};
data key = { 2, NULL };

data *result = SDL_bsearch_r(&key, values, SDL_arraysize(values), sizeof(values[0]), compare, (const void *)(uintptr_t)sort_increasing);

Function Parameters

key

a pointer to a key equal to the element being searched for.

base

a pointer to the start of the array.

nmemb

the number of elements in the array.

size

the size of the elements in the array.

compare

a function used to compare elements in the array.

userdata

a pointer to pass to the compare function.

Return Value

Returns a pointer to the matching element in the array, or NULL if not found.

Thread Safety

It is safe to call this function from any thread.

Availability

This function is available since SDL 3.2.0.

See Also

·(3), SDL_bsearch(3), ·(3), SDL_qsort_r(3)

Referenced By

SDL_bsearch(3), SDL_CompareCallback_r.3type(3), SDL_qsort_r(3).

SDL 3.2.2 Simple Directmedia Layer SDL3 FUNCTIONS