Missing IntelliSense Hover Docs

[Sbrjt]

Environment

• OS and Version: Windows 11 (Windows_NT 10.0.26120)
• VS Code Version: 1.101.2 (system setup)
• C/C++ Extension Version: 1.101.2 (system setup)
• If using SSH remote, specify OS of remote machine: --

Bug Summary and Steps to Reproduce

Bug Summary:

When I hover over the .assign() method, I don't see any doc comments.

But if i hover over .size(), I can see the doc comments.

Note that the source code is opened on the right and the comments are available.

Steps to reproduce:

• Start with a fresh profile and install the cpptools extension.
• Create this file and hover over the methods.

#include <vector>

int main(){
    std::vector<int> x = {1, 2, 3};

    x.size();
    x.assign(5, 2);
}

mingw was installed from choco. IntelliSense engine is set to default.

Expected behavior:

The official vs code docs include the following sample of IntelliSense hover:

Configuration and Logs

c_cpp_properties.json:

{
    "configurations": [
        {
            "name": "Win32",
            "includePath": [
                "${workspaceFolder}/**"
            ],
            "defines": [
                "_DEBUG",
                "UNICODE",
                "_UNICODE"
            ],
            "compilerPath": "C:/ProgramData/mingw64/mingw64/bin/g++.exe",
            "cStandard": "c17",
            "cppStandard": "c++17",
            "intelliSenseMode": "${default}"
        }
    ],
    "version": 4
}

-------- Diagnostics - 7/2/2025, 1:12:56 AM
Version: 1.26.3
Current Configuration:
{
    "name": "Win32",
    "includePath": [
        "c:/test/**"
    ],
    "defines": [
        "_DEBUG",
        "UNICODE",
        "_UNICODE"
    ],
    "compilerPath": "C:/ProgramData/mingw64/mingw64/bin/g++.exe",
    "cStandard": "c17",
    "cppStandard": "c++17",
    "compilerPathIsExplicit": true,
    "cStandardIsExplicit": true,
    "cppStandardIsExplicit": true,
    "intelliSenseModeIsExplicit": true,
    "recursiveIncludesReduceIsExplicit": false,
    "recursiveIncludesPriorityIsExplicit": false,
    "recursiveIncludesOrderIsExplicit": false,
    "compilerPathInCppPropertiesJson": "C:/ProgramData/mingw64/mingw64/bin/g++.exe",
    "mergeConfigurations": false,
    "recursiveIncludes": {},
    "browse": {
        "limitSymbolsToIncludedHeaders": true
    }
}
Additional Tracked Settings:
{
    "editorTabSize": 4,
    "editorInsertSpaces": true,
    "editorAutoClosingBrackets": "languageDefined",
    "filesEncoding": "utf8",
    "filesAssociations": {},
    "filesExclude": {
        "**/.git": true,
        "**/.svn": true,
        "**/.hg": true,
        "**/.DS_Store": true,
        "**/Thumbs.db": true
    },
    "filesAutoSaveAfterDelay": false,
    "editorInlayHintsEnabled": true,
    "editorParameterHintsEnabled": true,
    "searchExclude": {
        "**/node_modules": true,
        "**/bower_components": true,
        "**/*.code-search": true
    },
    "workbenchSettingsEditor": "ui"
}
cpptools version (native): 1.26.3.0
Current database path: C:\USERS\HP\APPDATA\LOCAL\MICROSOFT\VSCODE-CPPTOOLS\6D557105B6435204EBF79CA22E0DF8DA\.BROWSE.VC.DB
Translation Unit Mappings:
[ C:\test\a.cpp - source TU]:
    C:\ProgramData\mingw64\mingw64\lib\gcc\x86_64-w64-mingw32\13.2.0\include\c++\bits\stl_vector.h
Translation Unit Configurations:
[ C:\test\a.cpp ]
    Process ID: 15136
    Memory Usage: 96 MB
    Compiler Path: C:\ProgramData\mingw64\mingw64\bin\g++.exe
    Include paths:
        system include: C:\ProgramData\mingw64\mingw64\lib\gcc\x86_64-w64-mingw32\13.2.0\include\c++
        system include: C:\ProgramData\mingw64\mingw64\lib\gcc\x86_64-w64-mingw32\13.2.0\include\c++\x86_64-w64-mingw32
        system include: C:\ProgramData\mingw64\mingw64\lib\gcc\x86_64-w64-mingw32\13.2.0\include\c++\backward
        system include: C:\ProgramData\mingw64\mingw64\lib\gcc\x86_64-w64-mingw32\13.2.0\include
        system include: C:\ProgramData\mingw64\mingw64\lib\gcc\x86_64-w64-mingw32\13.2.0\include-fixed
        system include: C:\ProgramData\mingw64\mingw64\x86_64-w64-mingw32\include
    Defines:
        _DEBUG
        UNICODE
        _UNICODE
    Standard Version: c++17
    IntelliSense Mode: windows-gcc-x64
    Other Flags:
        --g++
        --gnu_version=130200
Total Memory Usage: 96 MB

------- Workspace parsing diagnostics -------
Number of files discovered (not excluded): 2578
Number of files parsed: 389

Other Extensions

None; it's a fresh profile.

Additional context

No response

[sean-mcmanus]

@Sbrjt It's caused by the macro after the comment (it becomes fixed if the return type and function are moved onto the same line as the macro). I've reported https://developercommunity.visualstudio.com/t/C-documentation-comments-dont-appear/10930993 , but I think it's already a known "by design" limitation with the doc comment implementation.

[Sbrjt]

@sean-mcmanus Then why is it working in the demo?

[sean-mcmanus]

@Sbrjt I don't know. It could be because it was using an older version of the headers that didn't have a macro between the comment and the function name.