FIX: Set C++ standard to 17

[iacore]

I had to set this to make it build, otherwise g++ complains about std::string_view being used but not being part of C++14.

Checks

• My commits follow the commit guidelines

[Krzmbrzl]

Unfortunately, we can't upgrade to C++17 yet. Not all of our code builds with it on all platforms.

[iacore]

Unfortunately, we can't upgrade to C++17 yet. Not all of our code builds with it on all platforms.

That's the same now isn't it? https://github.com/mumble-voip/mumble/blob/master/docs/dev/build-instructions/build_linux.md makes no mention of needing to tweak C++ version to build Mumble.

[Krzmbrzl]

You don't need to adapt anaything as the project is set up to compile using the C++14 standard.

[iacore]

You don't need to adapt anaything as the project is set up to compile using the C++14 standard.

The problem is exactly that GCC (g++) doesn't let me build the project using C++14. Newer protobuf library requires absl::string_view requires std::string_view (only in C++17).

Here: compile_log.txt

I suggest we vendor protobuf in such a case, since Google does not care about other people using their code.

[Krzmbrzl]

The problem is known but vendoring Protobuf is not really an option since we want to upgrade to C++17 anyway (once possible). Until then, specific environments require manual C++ standard overwrite

[iacore]

Can you document this in the Linux build .md file somehow?

[iacore]

I thought about this, and this issue is caused by abesil disrespecting C++ standard set. abesil is used by protobuf. Are you sure you don't want to use another protobuf library?

[davidebeatrici]

Are you aware of a valid alternative?

[iacore]

Compared to other languages, I "never" used C++.

Protocol-wise, there is FlatBuffers, capnproto, protobuf-c. Still, it is easier to specify a known version of protobuf (C++ library) and abesil in CMake and fetch from network when needed.

[Krzmbrzl]

There is no way for us to switch away from Protobuf. That would absolutely wreck backwards compatibility. Also, it is working rather well.

[iacore]

Understood.

[Krzmbrzl]

Using FetchContent might be an idea but distributors will likely not agree with this route at all - they tend to want to use the libraries packaged with a given OS.