Update codebase migration progress from C++11 to C++17/20

[GermanAizek]

@KOLANICH, @alex19EP review my pull request and feedback me.

[KOLANICH]

-return std::shared_ptr<language>(new some_language(*this)); //*this is specialized language info for that lang
+return std::make_shared<language>(*this);

looks like it creates the objects of superclass instead of objects of specialized classes. IDK if it is OK, but IMHO if it is, then the specialized classes should be eliminated in a separate PR.

[GermanAizek]

Windows build:

src\core\config.cpp(51): error C2429: language feature 'structured bindings' requires compiler flag '/std:c++17'

Linux build:

src/include/core/dtree.hpp:255:21: note: 'std::make_unique' is only available from C++14 onwards

@KOLANICH, I thought there was support for new standard, I saw a mention here:

RHVoice/CMakeLists.txt

Lines 32 to 38 in 219f846

	if(${CMAKE_VERSION} VERSION_GREATER "3.12")
	set(CMAKE_CXX_STANDARD 20)
	else()
	set(CMAKE_CXX_STANDARD 17)
	endif()

[alex19EP]

Windows build:

src\core\config.cpp(51): error C2429: language feature 'structured bindings' requires compiler flag '/std:c++17'

Linux build:

src/include/core/dtree.hpp:255:21: note: 'std::make_unique' is only available from C++14 onwards

@KOLANICH, I thought there was support for new standard, I saw a mention here:

RHVoice/CMakeLists.txt

Lines 32 to 38 in 219f846

	if(${CMAKE_VERSION} VERSION_GREATER "3.12")
	set(CMAKE_CXX_STANDARD 20)
	else()
	set(CMAKE_CXX_STANDARD 17)
	endif()

hello. in cmake yes. but hour CI uses scons.

since we're not using all the features of c++11 yet, I'm not sure if switching to a newer standard is a good idea.

[GermanAizek]

@alex19EP, if you set up a CI for new standard, I can do a code modernize?

[alex19EP]

as I already said

since we're not using all the features of c++11 yet, I'm not sure if switching to a newer standard is a good idea.

if you want to work on it, you can do some research on cpp11 features. offhand, it seems to me that we can abandon the self-made thread class ...

[Olga-Yakovleva]

I've just thought of the limitations this may put on Linux support. Which distros that may still be in use may not have new enough compilers? I'm not really familiar with this. For example, will Debian stable be OK with this? OR older Ubuntus which are still supported by Canonical?

[alex19EP]

will Debian
stable be OK with this?

lets ask @sthibaul

[sthibaul]

debian's default gcc will be at least gcc-12

[sthibaul]

debian's current stable gcc is gcc-10