eb4b9d1 make fails for primus_vk.cpp

[bclaesen]

Just tried to make eb4b9d1 and I get the following error. I'm sorry if this is me not understanding the compiler, but the previous version compiled without issues.

primus_vk.cpp: In member function ‘std::tuple<long int, long int, long int> PrimusSwapchain::getImageMemories()’:
primus_vk.cpp:939:62: error: converting to ‘std::tuple<long int, long int, long int>’ from initializer list would use explicit constructor ‘constexpr std::tuple< <template-parameter-1-1> >::tuple(_UElements&& ...) [with _UElements = {long int&, long int&, long int&}; <template-parameter-2-2> = void; _Elements = {long int, long int, long int}]’
   return {render_local_mem, render_host_mem, display_host_mem};

g++ --version
g++ (Ubuntu 5.4.0-6ubuntu1~16.04.11) 5.4.0 20160609

Edit: Seems to be fixed with using return std::make_tuple(...)
Edit: #50 added.

[felixdoerre]

The problem seems to be the old gcc, that's why I don't get this error. Thanks for the PR!