引入mimalloc头文件编译报错：std中无mi_realloc成员

我尝试在项目的common.hpp中通过包含mimalloc-new-delete.h和mimalloc-override.h来使用mimalloc，代码如下：

#pragma once
#ifndef _common_hpp
#define _common_hpp

#define SOL_ALL_SAFETIES_ON 1

#include <mimalloc-new-delete.h>
#include <mimalloc-override.h>

extern "C" {
#include <SDL2/SDL.h>
#include <avif/avif.h>
#include <curl/curl.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <physfs.h>
}

#include <algorithm>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>

#include <fmt/core.h>
#include <sol/sol.hpp>

#include "constants.hpp"
#include "deleters.hpp"
#include "types.hpp"

#endif

编译时出现如下错误：

-- Build files have been written to: /opt/workspace/carimbolabs/carimbo/build
[  4%] Building CXX object CMakeFiles/carimbo.dir/cmake_pch_arm64.hxx.pch
In file included from <built-in>:1:
In file included from /opt/workspace/carimbolabs/carimbo/build/CMakeFiles/carimbo.dir/cmake_pch_arm64.hxx:5:
In file included from /opt/workspace/carimbolabs/carimbo/src/application.hpp:5:
In file included from /opt/workspace/carimbolabs/carimbo/src/audiomanager.hpp:5:
In file included from /opt/workspace/carimbolabs/carimbo/src/common.hpp:20:
In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/iostream:44:
In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/istream:165:
In file included from /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/ostream:172:
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/c++/v1/locale:2827:22: 错误：命名空间'std'中没有名为'mi_realloc'的成员；您是不是想直接使用'mi_realloc'？
    _Tp* __t = (_Tp*)std::realloc(__owns ? __b.get() : 0, __new_cap);
                     ^~~~~
/Users/skhaz/.conan2/p/b/mimal0a19b82323bd4/p/include/mimalloc.h:112:40: 注：'mi_realloc'在此处声明
mi_decl_nodiscard mi_decl_export void* mi_realloc(void* p, size_t newsize)      mi_attr_noexcept mi_attr_alloc_size(2);
                                       ^
1 error generated.
make[2]: *** [CMakeFiles/carimbo.dir/cmake_pch_arm64.hxx.pch] Error 1
make[1]: *** [CMakeFiles/carimbo.dir/all] Error 2
make: *** [all] Error 2

错误原因 #

mimalloc-override.h通过宏定义把全局的realloc替换成mi_realloc，但系统标准库的头文件（比如这里的<locale>）中存在std::realloc的调用，宏替换只会处理无命名空间前缀的realloc，导致编译时编译器试图查找std::mi_realloc，而这个符号并不存在。

解决办法 #

方法1：调整头文件包含顺序 #

把系统标准库的C++头文件（<iostream>、<algorithm>等）放在mimalloc的头文件之前包含，这样当mimalloc的替换宏生效时，系统标准库的代码已经完成预处理，不会被影响。修改后的common.hpp示例：

#pragma once
#ifndef _common_hpp
#define _common_hpp

#define SOL_ALL_SAFETIES_ON 1

// 先包含系统C++标准库头文件
#include <algorithm>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>

// 再包含mimalloc相关头文件
#include <mimalloc-new-delete.h>
#include <mimalloc-override.h>

extern "C" {
#include <SDL2/SDL.h>
#include <avif/avif.h>
#include <curl/curl.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <physfs.h>
}

#include <fmt/core.h>
#include <sol/sol.hpp>

#include "constants.hpp"
#include "deleters.hpp"
#include "types.hpp"

#endif

方法2：仅替换C++的new/delete（不覆盖C标准库分配函数） #

如果不需要替换C标准库的malloc/realloc/free，可以只包含mimalloc-new-delete.h，同时定义MI_MALLOC_DISABLE_OVERRIDE宏来禁用mimalloc-override.h的替换功能：

#pragma once
#ifndef _common_hpp
#define _common_hpp

#define SOL_ALL_SAFETIES_ON 1
#define MI_MALLOC_DISABLE_OVERRIDE 1 // 禁用C标准库分配函数的替换

#include <mimalloc-new-delete.h>
// 不再包含mimalloc-override.h

extern "C" {
#include <SDL2/SDL.h>
#include <avif/avif.h>
#include <curl/curl.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <physfs.h>
}

#include <algorithm>
#include <iostream>
#include <list>
#include <map>
#include <memory>
#include <mutex>
#include <string>
#include <unordered_map>

#include <fmt/core.h>
#include <sol/sol.hpp>

#include "constants.hpp"
#include "deleters.hpp"
#include "types.hpp"

#endif

内容的提问来源于stack exchange，提问作者Rodrigo