OS X: C++ 11 make_unique

[RaymiiOrg]

As I saw in the github actions pull request (#26 ), compilation with clang on OS X fails due to not having a make_unique (which is a C++ 14 feature). This is a workaround which should do the same.

[lenticularis39]

It's a little ironic that it was me who wanted to target C++11 instead of C++14 and then I break macOS by std::make_unique, which is apparently a C++14 feature (didn't know that before) :D

Anyway the include of make_unique.h should IMO be in StdAfx.hpp (also make_unique.h should be named make_unique.hpp).

Also checking specifically for __APPLE__ doesn't sound right - there may be (now or in the future) a situation where std::make_unique is present. Checking for C++ standard below 14 using #if __cplusplus < 201402L should be better - it may still fail on older compilers that support only a part of C++14 including std::make_unique, though.

[RaymiiOrg]

It's a little ironic that it was me who wanted to target C++11 instead of C++14 and then I break macOS by std::make_unique, which is apparently a C++14 feature (didn't know that before) :D

Anyway the include of make_unique.h should IMO be in StdAfx.hpp (also make_unique.h should be named make_unique.hpp).

Also checking specifically for __APPLE__ doesn't sound right - there may be (now or in the future) a situation where std::make_unique is present. Checking for C++ standard below 14 using #if __cplusplus < 201402L should be better - it may still fail on older compilers that support only a part of C++14 including std::make_unique, though.

Updated branch with both changes. I agree that it's better to check for the older compiler instead of just apple. Thanks for the #if example!

Apple build now succeeds: https://github.com/RaymiiOrg/axpbox/runs/1422659565?check_suite_focus=true - tests not yet but that is for a different ticket.