设置搜索这几个，并设置为对应值。

如果没解决，可能是clangd的问题。

禁用clangd，然后去看看c_cpp_properties.json。

看complierPath是不是clang。 如果是，改成g++/gcc。

再看一下intelliSenseMode是不是clang。如果是，改为default。

linux下c_cpp_properties.json的配置

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "/usr/include",
                "/usr/local/include",
                "${workspaceFolder}/**"
            ],
            "defines": [],
            "compilerPath": "/usr/bin/g++",
            "cStandard": "c23",
            "cppStandard": "c++20",
            "browse":{"path":[
                "/usr/include",
                "/usr/local/include",
                "${workspaceFolder}/**"
            ]
         },
            "intelliSenseMode": "${default}"
        }
    ],
    "version": 4
}

windows下c_cpp_properties.json的配置

{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "D:/programme/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/include/c++",
                "D:/programme/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/include/c++/x86_64-w64-mingw32",
                "D:/programme/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/include/c++/backward",
                "D:/programme/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/include",
                "D:/programme/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/include-fixed",
                "D:/programme/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/include"
            ],
            "defines": [
                "_DEBUG",
                "UNICODE",
                "_UNICODE"
            ],
            "compilerPath": "D:\\programme\\mingw64\\bin\\g++.exe",
            "cStandard": "c23",
            "cppStandard": "c++23",
            "intelliSenseMode": "windows-gcc-x64"
        },
    "version": 4
}

如果嫌vscode自带的补全太慢，可以更改以下设置（默认为10，建议改到5以下）

参考文章：

VSCode C/C++无法跳转到定义、自动补全、悬停提示功能

VSCode代码自动补全太慢的问题

vscode解决自动补全突然失效的问题(c++)