C++ IDE for Macs

Emacs! Eclipse might work too.

Code::Blocks is cross-platform, using the wxWidgets library. It's the one I use.

Xcode which is part of the MacOS Developer Tools is a great IDE. There's also NetBeans and Eclipse that can be configured to build and compile C++ projects.

Clion from JetBrains, also is available now, and uses Cmake as project model.