Compiling 32-bit vs 64-bit project using CMake

Question

How do I specify that CMake should use a different link_directories value depending on whether the target is 32-bit or 64-bit? For example, 32-bit binaries need

Answer 1

I know it's quite old question. But it's still on top when you search with Google "cmake 32 64". I have answer similar to user434507's answer but a little bit more readable in my opinion (I don't like if-else construction in cmake, it looks ugly):

math(EXPR BITS "8*${CMAKE_SIZEOF_VOID_P}")
set(BOOST_LIBRARY "/boost/win${BITS}/lib")
set(CMAKE_EXE_LINKER_FLAGS ${BOOST_LIBRARY})

This will point BOOST_LIBRARY path to /boost/win32/lib or /boost/win64/lib, depending on your architecture.