#include <boost/bind/apply.hpp> #include <boost/optional.hpp> Results in: dev/boost/boost/optional/optional.hpp: In member function 'void boost::optional_detail::optional_bas e<T>::construct(const Expr&, const boost::in_place_factory_base*)': dev/boost/boost/optional/optional.hpp:309: error: invalid use of 'struct boost::apply<T>' On GCC4.0.2. The offending line is: factory.BOOST_NESTED_TEMPLATE apply<value_type>(m_storage.address()) ; A simple fix is to move the apply() call out of the boost namespace. The attached patch fixes the problem. OK to commit? -- Daniel Wallin Index: optional.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/optional/optional.hpp,v retrieving revision 1.9 diff -u -r1.9 optional.hpp --- optional.hpp 10 Feb 2006 20:52:25 -0000 1.9 +++ optional.hpp 18 Mar 2006 11:40:32 -0000 @@ -76,6 +76,16 @@ #define BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION #endif +namespace boost_optional_construct +{ + + template <class T, class Factory> + void construct(Factory const& factory, void* address) + { + factory.BOOST_NESTED_TEMPLATE apply<T>(address); + } + +} // namespace boost_optional_construct namespace boost { @@ -295,7 +305,9 @@ void construct ( Expr const& factory, in_place_factory_base const* ) { BOOST_STATIC_ASSERT ( ::boost::mpl::not_<is_reference_predicate>::value ) ; - factory.BOOST_NESTED_TEMPLATE apply<value_type>(m_storage.address()) ; + boost_optional_construct::construct<value_type>( + factory, m_storage.address() + ); m_initialized = true ; }