[boost] [test] CHECK_EQUAL and problem with class constants

Consider this simple example... #include <boost/test/test_tools.hpp> struct Foo { static unsigned int const x = 10; }; int test_main( int, char* [] ) // note the name! { BOOST_CHECK_EQUAL(10U, Foo::x); return 0; } At least under gcc, I get a linker error, unable to find Foo::x, while the following code works fine... int test_main( int, char* [] ) // note the name! { BOOST_CHECK(10U == Foo::x); return 0; }