On Tue, 8 Dec 2009, Stewart, Robert wrote:
Can anyone figure out why GCC 3.3.3 doesn't like the following member function overloads? VC7/8/9 and GCC 4.1.2 have no problems with this code.
#include <boost/mpl/and.hpp> #include <boost/mpl/not.hpp> #include <boost/type_traits/is_const.hpp> #include <boost/type_traits/is_convertible.hpp> #include <boost/utility/enable_if.hpp>
struct Bar { };
template <class T> struct Baz { };
struct Foo { template <class T> typename boost::enable_if < boost::mpl::and_ < boost::is_convertible<T,Bar> , boost::mpl::not_<boost::is_const<T> > >
::type set(Baz<T> const & _value);
template <class T> typename boost::enable_if < boost::mpl::and_ < boost::is_convertible<T,Bar> , boost::is_const<T> >
::type set(Baz<T> const &); };
GCC 3.3.3's error message is:
error: `template<class T> typename boost::enable_if<boost::mpl::and_<boost::is_convertible<T, Bar>, boost::is_const<T>, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true>
, void>::type Foo::set(const Baz<T>&)' and `template<class T> typename boost::enable_if<boost::mpl::and_<boost::is_convertible<T, Bar>, boost::mpl::not_<boost::is_const<T> >, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true> >, void>::type Foo::set(const Baz<T>&)' cannot be overloaded
The functions are too similar for GCC 3.3. Please look at Section 3.4 of http://www.boost.org/doc/libs/1_41_0/libs/utility/enable_if.html for more information and workarounds. -- Jeremiah Willcock