如何在Visual代码中包含C++20模块

Question

我正在用Visual代码编写C++20代码。我的配置如下所示：

文件c_cpp_properties.json

{
    "configurations": [
        {
            "name": "Mac",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [],
            "macFrameworkPath": [
                "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks"
            ],
            "compilerPath": "/usr/local/Cellar/gcc/10.2.0/bin/g++-10",
            "cStandard": "c11",
            "cppStandard": "c++20",
            "intelliSenseMode": "clang-x64"
        }
    ],
    "version": 4
}

文件tasks.json

{
    "version": "2.0.0",
    "tasks": [
        {
            "type": "cppbuild",
            "label": "C/C++: clang++ build active file",
            "command": "/usr/local/Cellar/gcc/10.2.0/bin/g++-10",
            "args": [
                "-g",
                "-pthread",
                "-std=c++20",
                "-I/usr/local/Cellar/gcc/10.2.0/include",
                "-I/usr/local/Cellar/fmt/7.1.3/include",
                "${file}",
                "-o",
                "${fileDirname}/${fileBasenameNoExtension}"
            ],
            "options": {
                "cwd": "${workspaceFolder}"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": {
                "kind": "build",
                "isDefault": true
            },
            "detail": "Task generated by Debugger."
        }
    ]
}

在我尝试使用syncstream之前，一切看起来都很好，这是在C++20中引入的。

当我运行#include <syncstream>时，编译器总是给出一个错误：

fatal error: syncstream: No such file or directory
    5 | #include <syncstream>
      |          ^~~~~~~~~~~~
compilation terminated.

如何在Visual代码中进行配置，以便编译器可以使用C++20模块？

Answer 1

参见https://en.cppreference.com/w/cpp/compiler_support#C.2B.2B20_library_features中的“同步缓冲的ostream”

您需要libstdc++11。您的编译器(g++10)还不支持syncstream。