[MSVC] CoreCLR failed to build due to error C2280 and C2088 with option /std:c++20

[Zhaojun-Liu]

Description

CoreCLR failed to build with MSVC due to error C2280 and error C2088 with option /std:c++20, detailed error message as follows:

F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2280: 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const wchar_t *)': attempting to reference a deleted function
  C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.35.32215\include\ostream(971): note: see declaration of 'std::operator <<'
  F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2088: '<<': illegal for class

Reproduction Steps

1. git clone https://github.com/dotnet/runtime F:\gitP\dotnet\runtime
2. git -C "F:\gitP\dotnet\runtime" reset --hard b90c9cf
3. set CL=/std:c++latest /permissive /wd5054 /wd5055 /wd5033 /D_HAS_STD_BYTE=0 /Zc:equalityRewrite-
4. cd F:\gitP\dotnet\runtime
5. .\build.cmd -subset clr+libs -c release -arch x64

Expected behavior

Build successfully.

Actual behavior

F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\hostpolicy_exports.cpp(11): error C2280: 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const wchar_t *)': attempting to reference a deleted function
  C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.35.32215\include\ostream(971): note: see declaration of 'std::operator <<'
  F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\hostpolicy_exports.cpp(11): error C2088: '<<': illegal for class
F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2280: 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const wchar_t *)': attempting to reference a deleted function
  C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.35.32215\include\ostream(971): note: see declaration of 'std::operator <<'
  F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2088: '<<': illegal for class

Regression?

No response

Known Workarounds

add option /D_HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20，the error will disappear.

Configuration

OS: Windows Server 2022
VS: VS2022 17.5.4
.NET 8.0

Other information

No response

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Issue Details

---

Description

CoreCLR failed to build with MSVC due to error C2280 and error C2088 with option /std:c++20, detailed error message as follows:

F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2280: 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const wchar_t *)': attempting to reference a deleted function
  C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.35.32215\include\ostream(971): note: see declaration of 'std::operator <<'
  F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2088: '<<': illegal for class

Reproduction Steps

1. git clone https://github.com/dotnet/runtime F:\gitP\dotnet\runtime
2. git -C "F:\gitP\dotnet\runtime" reset --hard b90c9cf
3. set CL=/std:c++latest /permissive /wd5054 /wd5055 /wd5033 /D_HAS_STD_BYTE=0 /Zc:equalityRewrite-
4. cd F:\gitP\dotnet\runtime
5. .\build.cmd -subset clr+libs -c release -arch x64

Expected behavior

Build successfully.

Actual behavior

F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\hostpolicy_exports.cpp(11): error C2280: 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const wchar_t *)': attempting to reference a deleted function
  C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.35.32215\include\ostream(971): note: see declaration of 'std::operator <<'
  F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\hostpolicy_exports.cpp(11): error C2088: '<<': illegal for class
F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2280: 'std::basic_ostream<char,std::char_traits<char>> &std::operator <<<std::char_traits<char>>(std::basic_ostream<char,std::char_traits<char>> &,const wchar_t *)': attempting to reference a deleted function
  C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.35.32215\include\ostream(971): note: see declaration of 'std::operator <<'
  F:\gitP\dotnet\runtime\src\native\corehost\test\nativehost\comhost_test.cpp(64): error C2088: '<<': illegal for class

Regression?

No response

Known Workarounds

add option /D_HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20，the error will disappear.

Configuration

OS: Windows Server 2022
VS: VS2022 17.5.4
.NET 8.0

Other information

No response

Author:	Zhaojun-Liu
Assignees:	-
Labels:	area-Host
Milestone:	-

[elinor-fung]

Looks like the test code is actually using mismatched types in those lines - it would have printed garbage to the output if it hit those error cases. I think those stream overloads were deleted in newer versions precisely to make it harder to accidentally do this.