Check if given C++ source compiles and links into an executable

CHECK_CXX_SOURCE_COMPILES(<code> <var> [FAIL_REGEX <fail-regex>])

<code>       - source code to try to compile, must define 'main'
<var>        - variable to store whether the source code compiled
<fail-regex> - fail if test output matches this regex

The following variables may be set before calling this macro to modify the way the check is run:

CMAKE_REQUIRED_FLAGS = string of compile command line flags
CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
CMAKE_REQUIRED_INCLUDES = list of include directories
CMAKE_REQUIRED_LIBRARIES = list of libraries to link