编辑“︁C++ new 和delete 重载”︁（章节）

=== 内存泄漏检测 ===

通过重载new和delete可以实现简单的内存泄漏检测：

<syntaxhighlight lang="cpp">
#include <iostream>
#include <map>

std::map<void*, size_t> allocations;

void* operator new(size_t size) {
    void* ptr = malloc(size);
    allocations[ptr] = size;
    std::cout << "分配: " << ptr << " (" << size << " 字节)\n";
    return ptr;
}

void operator delete(void* ptr) noexcept {
    auto it = allocations.find(ptr);
    if (it != allocations.end()) {
        std::cout << "释放: " << ptr << " (" << it->second << " 字节)\n";
        allocations.erase(it);
    }
    free(ptr);
}

void checkLeaks() {
    if (!allocations.empty()) {
        std::cerr << "内存泄漏检测到 " << allocations.size() << " 个未释放块:\n";
        for (const auto& [ptr, size] : allocations) {
            std::cerr << "  " << ptr << ": " << size << " 字节\n";
        }
    }
}
</syntaxhighlight>