David Abrahams wrote:
Still no dice for vc7.1, though.
Hum, that was too easy: #include <boost/static_assert.hpp> typedef char yes; typedef char (&no)[2]; template <class T> yes is_nonconst_rvalue(T const&, ...); template <class T> no is_nonconst_rvalue(T&, int); struct foo { #ifndef BOOST_MSVC template<typename U> operator U() const; template<typename V> operator V& () volatile const ; #else template<typename U> operator U() volatile; template<typename V> operator V& () const ; #endif static foo const instance; static bool select; }; #define IS_RVALUE(x) \ (sizeof(is_nonconst_rvalue((foo::select ? foo::instance : (x)), 0)) == sizeof(yes)) int rvalue(); int const_rvalue(); int& lvalue(); int const& const_lvalue(); int volatile volatile_rvalue(); int const_volatile_rvalue(); int volatile& volatile_lvalue(); int const volatile& const_volatile_lvalue(); BOOST_STATIC_ASSERT(IS_RVALUE(rvalue())); BOOST_STATIC_ASSERT(IS_RVALUE(const_rvalue())); BOOST_STATIC_ASSERT(!IS_RVALUE(lvalue())); BOOST_STATIC_ASSERT(!IS_RVALUE(const_lvalue())); BOOST_STATIC_ASSERT(IS_RVALUE(volatile_rvalue())); BOOST_STATIC_ASSERT(IS_RVALUE(const_volatile_rvalue())); BOOST_STATIC_ASSERT(!IS_RVALUE(volatile_lvalue())); BOOST_STATIC_ASSERT(!IS_RVALUE(const_volatile_lvalue())); -- Dave Abrahams Boost Consulting http://www.boost-consulting.com