[Experiment] boost::typeindex::type_index & unnamed namespace

[rwgk]

Description

Related to PR #4313

Suggested changelog entry:

[rwgk]

The CI results for the current commit are here (everything succeeded):

https://github.com/pybind/pybind11/actions/runs/3404002038/jobs/5660924568

The name of the "Download log archive" file: logs_24752.zip

Results of inspecting the logs are below.

Unfortunately we do not have great coverage for PYBIND11_TEST_BOOST, in particular Windows and clang.

Local testing with clang-12 under Debian resulted in boost::typeindex::type_index-EQ-BAD

Summary:

• boost::typeindex::type_index does not appear to help for clang.
• MSVC is still unknown.

Giving up, because clearly boost::typeindex::type_index does not provide a universal solution. Knowing about MSVC would be nice, but not change very much w.r.t. #4313.

$ grep boost::typeindex::type_index-NE-GOOD *.txt | sed 's/^[1-9][0-9]*//' | cutniq | sort
______3.10_____ubuntu-latest_____x64.txt
______3.11_____ubuntu-latest_____x64.txt
______3.9_____ubuntu-latest_____x64.txt
______3_____windows-latest_____mingw32.txt
______3_____windows-latest_____mingw64.txt
______pypy-3.7_____ubuntu-latest_____x64.txt
______pypy-3.8_____ubuntu-latest_____x64_-DPYBIND11_FINDPYTHON=ON.txt
______pypy-3.9_____ubuntu-latest_____x64.txt

$ grep boost::typeindex::type_index-EQ-BAD *.txt | sed 's/^[1-9][0-9]*//' | cutniq | sort
______3.10_____macos-latest_____x64.txt
______3.11_____macos-latest_____x64.txt
______3.6_____macos-latest_____x64.txt
______3.9_____macos-latest_____x64.txt
______pypy-3.7_____macos-latest_____x64.txt
______pypy-3.8_____macos-latest_____x64.txt
______pypy-3.9_____macos-latest_____x64.txt

$ grep boost::typeindex::type_index-NotAvailable *.txt | sed 's/^[1-9][0-9]*//' | cutniq
______3.10_____CUDA_11.7_____Ubuntu_22.04.txt
______3.10_____windows-2022_____x64.txt
______3.11__deadsnakes______x64.txt
______3.11_____windows-2022_____x64.txt
______3.6_____MSVC_2019_____x86.txt
______3.6_____ubuntu-latest_____x64_-DPYBIND11_FINDPYTHON=ON_-DCM.txt
______3.6_____windows-2019_____x64_-DPYBIND11_FINDPYTHON=ON.txt
______3.6_____windows-2022_____x64.txt
______3.7_____Debian_____x86______Install.txt
______3.7_____MSVC_2019_____x86_-DCMAKE_CXX_STANDARD=14.txt
______3.8_____MSVC_2019__Debug______x86_-DCMAKE_CXX_STANDARD=17.txt
______3.8_____MSVC_2019_____x86_-DCMAKE_CXX_STANDARD=17.txt
______3.9-dbg__deadsnakes______Valgrind_____x64.txt
______3.9_____MSVC_2019__Debug______x86_-DCMAKE_CXX_STANDARD=20.txt
______3.9_____MSVC_2019_____x86_-DCMAKE_CXX_STANDARD=20.txt
______3.9_____MSVC_2022_C++20_____x64.txt
______3.9_____windows-2019_____x64.txt
______3.9_____windows-2022_____x64.txt
______3_____almalinux8_____x64.txt
______3_____almalinux9_____x64.txt
______3_____CentOS7__PGI_22.9_____x64.txt
______3_____centos7_____x64.txt
______3_____Clang_10_____C++17_____x64.txt
______3_____Clang_10_____C++20_____x64.txt
______3_____Clang_11_____C++20_____x64.txt
______3_____Clang_12_____C++20_____x64.txt
______3_____Clang_13_____C++20_____x64.txt
______3_____Clang_14_____C++20_____x64.txt
______3_____Clang_3.6_____C++11_____x64.txt
______3_____Clang_3.7_____C++11_____x64.txt
______3_____Clang_3.9_____C++11_____x64.txt
______3_____Clang_5_____C++14_____x64.txt
______3_____Clang_7_____C++11_____x64.txt
______3_____Clang_9_____C++11_____x64.txt
______3_____Clang_dev_____C++11_____x64.txt
______3_____GCC_10_____C++17____x64.txt
______3_____GCC_11_____C++20____x64.txt
______3_____GCC_12_____C++20____x64.txt
______3_____GCC_7_____C++11____x64.txt
______3_____GCC_7_____C++17____x64.txt
______3_____GCC_8_____C++14____x64.txt
______3_____GCC_8_____C++17____x64.txt
______3_____ICC_latest_____x64.txt
______pypy-3.7_____windows-2022_____x64.txt
______pypy-3.8_____windows-2022_____x64.txt
______pypy-3.9_____windows-2022_____x64.txt