Putting CMake binaries in a specific directory

I've started using CMake for pretty much all my development work and have been quite happy except for a few minor issues.  One of those is that the build-products are put in Debug and Release directories by default, instead of single output directory. You can add an install target to do this, but XCode won't apply it through the UI. Ditto goes for a post-build copy step.

It took a while to find, but it's actually simple to get binaries placed into a directory of your choosing. In the example project, code and the CMakeLists.txt file is in the code/ subdirectory, I build using CMake/XCode in the build/ subdirectory and I want the build products placed in the bin/ subdirectory, regardless of whether they are built as debug or release.

Here's the CMakeLists.txt file:

cmake_minimum_required( VERSION 2.6 )

project( entropy )

add_executable( entropy main.cpp )
target_link_libraries( entropy ${LIBS} )
set_target_properties( entropy PROPERTIES
  RUNTIME_OUTPUT_DIRECTORY_DEBUG   ${CMAKE_SOURCE_DIR}/../bin 
  RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_SOURCE_DIR}/../bin
)

The set_target_properties() command allows you to set the runtime output directory. You'll see this a fix similar to this online in many places, but it will put the built executables in bin/Debug or bin/Release, instead of just bin/. What was not immediately obvious is that it can be set per-build-configuration, causing all build products to be put in bin/.