I can confirm that C++ Rest SDK v2.1 works great on CentOS 7.
Most requisite packages are already installed if you installed CentOS 7 with minimal install option and chose developer role. You'll need a few more:
sudo yum install cmake boost-devel openssl-devel
sudo yum update
The remaining steps are similar to Ubuntu instructions.
git clone https://git01.codeplex.com/casablanca
Build the SDK for Release
CXX=g++ cmake .. -DCMAKE_BUILD_TYPE=Release
Run the tests. They all passed on my system.