Bound checked array

#include <stdio.h>
#include <stdint.h>
#include <assert.h>

static_assert(sizeof(void *) == 8);

struct array32{
    char unsafe[32];
    char& operator [](uint64_t index)
    {
        assert(index < 32);
        return unsafe[index];
    }
};

static
array32 array32_set_safe(char *a)
{
    array32 result;
    int stringLength = snprintf(result.unsafe, 32, "%s", a);
    assert(stringLength >= 0 && stringLength < 32);
    return result;
}

int main(void) {
    
    array32 eple = array32_set_safe("123456789012345678901234567890a");
    
    printf("%s, %li\n", eple.unsafe, sizeof(array32));
    return 0;
}