compat.mimalloc

// compat.mimalloc — assert the allocator is real, not just that it links.
//
// Every check below can fail: mi_usable_size reports what mimalloc actually
// reserved (so it proves the pointer came from mimalloc's own bookkeeping and
// not from a fallback), mi_zalloc must return zeroed memory, and a private
// heap must be able to hand out and destroy blocks independently of the
// default heap.
#include <mimalloc.h>
import std;

int main() {
    bool ok = true;

    auto check = [&](bool cond, std::string_view what) {
        if (!cond) {
            std::println("FAIL: {}", what);
            ok = false;
        }
    };

    // 1. Basic allocation, and mimalloc knows the block's real size.
    void* p = mi_malloc(1024);
// …