[CMake] How to refer to current configuration?

[Timothy Reaves]

	I have a project that produces a dynamic library.  This gets built to a directory that in the src tree.  Specifically, it is put in a subdirectory of src that is the same as the name of the active configuration.  So if I am building a debug release, the path is src/Debug/my.dylib, and for release, it's src/Release/my.dylib.  My question is, what cmake variable refers to this location? The CMAKE_BINARY_DIR variable only refers to the src directory.