is_function return false for cv-qualified function types

[Peter Dimov]

As the following test shows:

#include <boost/type_traits/is_function.hpp>
#include <boost/core/lightweight_test_trait.hpp>

struct X
{
    void f() {}
    void fc() const {}
    void fv() volatile {}
    void fcv() const volatile {}
};

template< class C, class F > void test( F C::* )
{
    BOOST_TEST_TRAIT_TRUE(( boost::is_function< F > ));
}

int main()
{
    test( &X::f );
    test( &X::fc );
    test( &X::fv );
    test( &X::fcv );

    return boost::report_errors();
}

[John Maddock]

Confirmed and moved to ​https://github.com/boostorg/type_traits/issues/81