plusplus_cpplib_dir = $(plusplus_dir)
plusplus_runtime_dir = $(plusplus_cpplib_dir)\runtime
plusplus_string_dir = $(plusplus_cpplib_dir)\string
plusplus_complex_dir = $(plusplus_cpplib_dir)\complex
plusplus_iostream_dir = $(plusplus_cpplib_dir)\iostream
plusplus_contain_dir = $(plusplus_cpplib_dir)\contain
