gcc-10 / clang-10 compatibility break

[Buom01]

Hi,

I noticed a time ago that the repo doesn't build with GCC 10. As it's really difficult to have both gcc-10 and gcc-9 on a single Linux distro, I'm looking for a reliable solution for everyone.

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I thought about updating the code. Beginning by sol2 library, and as they said (here: https://sol2.readthedocs.io/en/latest/tutorial/getting-started.html ):

If you get an avalanche of errors (particularly referring to auto), you may not have enabled C++14 / C++17 mode for your compiler. Add one of std=c++17, std=c++1z OR std=c++1y to your compiler options. [...]

-std=c++1* is required (doesn't compile else, according to my tests).

As I didn't learn enough C++ (I will learn it soon at school), I'm not sure nor fine about all conversion that -std=c++17 and gcc-10 implies to other parts of code. I think that (as the make output said) it would need a some boring updates/changes in the code. Which may be long to do properly, and could make some things harder to import from forks.

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Finally, I think that nobody would make too many changes to an old project while, in a way, Stellar-Prey aim to drop compatibility and could make maintenance and programming a lot easier.
For now, I'm thinking a Docker container with gcc-9 is the quickest solution for development and doesn't require any changes.

(It would look like docker run -ti -v $(pwd):/anywhere mymakecontainer and could be aliased for easier dev purpose. It could also take arguments but maybe not environment variable without explicit -e argument.)

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So my question would be, how to handle GCC 10 ? What is the best approach ?

[wtfbbqhax]

@Buom01 if the issue is simply with --std=c++1y we can update that as appropriate.

Is there also an issue with sol2?

[wtfbbqhax]

FWIW, I think we should fix the build to work with the latest compiler toolchains in rotation-

[Buom01]

Sorry for the late reply.
I learned a lot more in C++ since, but I don't think to solve this issue nor the Makefile myself currently.
Building with the documented Docker's container work quite well enough at least as a temporary solution. (https://github.com/GrangerHub/tremulous#how-to-build-for-win64)

Is there also an issue with sol2?

Not really, I just failed to do a basic upgrade of it. As it may need tweaks to work with gcc-10 (or with the entire project)