use <version> (introduced in C++20) instead of <ciso646> (deprecated)

[trougnouf]

Use <version> (introduced in C++20) instead of <ciso646> (deprecated in C++17).

This fixes GCC15 compiler warnings in darknet, e.g.:

In file included from /home/trougnouf/aur/darknet-cpu/src/darknet/src-lib/darknet_internal.hpp:23,
                 from /home/trougnouf/aur/darknet-cpu/src/darknet/src-lib/col2im.cpp:2:
/usr/include/c++/15.1.1/ciso646:46:4: warning: #warning "<ciso646> is deprecated in C++17, use <version> to detect implementation-specific macros" [-Wcpp]
   46 | #  warning "<ciso646> is deprecated in C++17, use <version> to detect implementation-specific macros"
      |    ^~~~~~~

and also makes it possible to compile DarkHelp which failed due to -Werror

[stephanecharette]

Thing is, Darknet currently uses C++17. The version header is not available until C++20.

[trougnouf]

Thing is, Darknet currently uses C++17. The version header is not available until C++20.

Wouldn't the preprocessor check take care of it?

#if __has_include(<version>)
#  include <version>
#else
#  include <ciso646>
#endif

Somehow this compiles with no complaint (w/ GCC15 and I assume C++17 since I didn't change anything else) whereas leaving ciso646 gives a deprecation warning which turns into a compilation error in programs that treat warnings as such.
(Alternatively DarkHelp would have to disable the -Werror flag)