Change setting of minimum standard version

[PPokorski]

Hi! First of all thank you a lot for making this CMake version of Box2D. It was a great help for me to use it in my project, as I do not use premake.
Nevertheless I ran across a problem with this line:

Box2D-cmake/CMakeLists.txt

Line 57 in 65b7577

target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_17)

which requires CMake version of at least 3.8 (btw you require 3.5), which isn't bundled with, e.g. Ubuntu 16.04 LTS. I would suggest to change this line to

set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)

which would lower the requirements to CMake 3.1, I suppose (3.0 doesn't have CXX_STANDARD property).

Furthermore, original Box2D requires C++11 standard, so that's why I would suggest to keep it that way.

Thanks for your time and response!

[tobanteGaming]

@PPokorski

Sorry that I didn't see your issue earlier. It has been a while since I logged into this account.

I changed the minimum standard to C++11 to match the original build. However, I don't really want to add set set_property line since it's old CMake style and discouraged by the developers.

Thanks for taking the time to report these issues.

Toby

[PPokorski]

Thank you for your response. Well, maybe I'm really using an old version of CMake, but it's the one that's default-shipped with Ubuntu 16.04, so I thought it shouldn't be that bad. Well then, the decision is yours :) Thanks anyway.