-AC_MSG_RESULT([Using '$prefix' for installation.])
-AC_MSG_RESULT([Using '$CXX' for C++ compiler.])
-AC_MSG_RESULT([Building with '$CPPFLAGS' for C++ preprocessor flags.])
-AC_MSG_RESULT([Building with '$CXXFLAGS' for C++ compiler flags.])
-AC_MSG_RESULT([Building with '$LIBS' for linker flags.])