Bug: Spurious IntelliSense errors with C++20 Modules

Comienza con el ejemplo reproducible de C++20 Modules usando import std, import winrt_base y import winrt.Windows.Foundation en Visual Studio Insiders con MSVC 14.52 Preview. Compara el comportamiento de IntelliSense con el del proyecto equivalente basado en headers y revisa el winrt\base.h generado que se menciona en el error. Se considerará terminado si se identifica una solución alternativa en cppwinrt para los falsos positivos E1776 o se confirma que el problema debe resolverse en DevCom-11123562.

Version

3.0.260715.1

Summary

A simple project that uses C++/WinRT with the new C++20 Modules feature can build successfully with MSVC 14.52 Preview in Visual Studio Insiders, but has IntelliSense errors in the IDE that get in the way of return type deduction and similar. For instance, the example code causes this IntelliSense error:

function "winrt::Windows::Foundation::IUnknown::operator new(size_t)" (declared at line 2117 of module "winrt_base" ("D:\...\winrtmodcom\x64\Debug\Generated Files\winrt\base.h")) cannot be referenced -- it is a deleted function

More likely than not, this is simply an IDE and IntelliSense bug and I've reported it as such in DevCom-11123562. Anyone who cares about this scenario is welcome to upvote it. Having said that, if there's any workaround that can be implemented on the cppwinrt side to mitigate these IntelliSense failures, it would be a welcome improvement to the user experience.

Reproducible example

import std;
import winrt_base;
import winrt.Windows.Foundation;

winrt::Windows::Foundation::IAsyncOperation<winrt::hstring> GetStringAsync()
{
    co_return L"Hello, World!";
}

winrt::Windows::Foundation::IAsyncOperation<winrt::hstring> foo()
{
    auto str = co_await GetStringAsync(); // IntelliSense labels this <error type> instead of figuring out it is a winrt::hstring.
    co_return str;
}

Expected behavior

IntelliSense should be fully functional with cppwinrt C++20 Modules in scenarios that work correctly with header files.

Actual behavior

IntelliSense reports spurious E1776 errors and fails to deduce return types

Additional comments

No response