Check out http://runtimecompiledcplusplus.blogspot.com/. The code is available at https://github.com/RuntimeCompiledCPlusPlus/RuntimeCompiledCPlusPlus. At least one integration example to an existing game engine can be found http://urho3d.prophpbb.com/topic308.html.
Unsurprisingly since I'm the author of RCC++ it's also in my game http://www.avoyd.com
Lots of edits to this, as by heck is the editor great at losing what you type if it can't parse it.