Test failing on GCC and Clang

[Twon]

Hi Bengt,

Jon has added a branch which adds GitHub actions to build this project across Visual Studio, GCC and Clang for Windows, Linux and MacOS. We've noticed the test fails under GCC and Clang currently (please see here for details: https://github.com/jbcoe/PolymorphicValue/actions/runs/5169070294).

I have reproduced the failure locally, and will shortly raise a PR addressing one issue, but there appear to be a number of other failures which I am currently investigating.

I'll add more details to the PR and let me know if you have any questions.

Best wishes,
Antony

[BengtGustafsson]

Thanks for the effort. I'm aware that I only compiled this on VS, and may not have added /permissive- which actually detects most of the things that otherwise causes gcc/clang compilation to fail even if MSVC compiles it. I will check out your PRs now.