On 11/28/2012 6:14 AM, Mathias Gaunard wrote:
On 28/11/12 08:42, Oliver Kowalke wrote:
Hello, clang (c++11 support) fails on code like:
BOOST_STATIC_ASSERT(( is_same< void, typename result_of< Fn() >::type
::value));
with error:
no type named 'type' in 'boost::result_of<void (&())(X &)>' is_same< void, typename result_of< Fn() >::type
::value)); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~**~~
Does Fn == void (&)(X&) or void (X&) ? I.e., is it a unary function type?
it's called inside a templated function: template< typename Fn > void g(BOOST_RV_RV( Fn) fn){ BOOST_STATIC_ASSERT(...) ....}
remove the reference from Fn (at least in C++11). I don't know what the actual type of Fn is in C++03.
Did my previous answer not fully address this issue? The function type void(&)(X&) cannot be called with 0 arguments, so a decltype-based result_of will have the behavior your observe. The old TR1-style result_of will give you void. At present, decltype-based result_of is only enabled for very recent clang builds. This explains the difference. -- Eric Niebler BoostPro Computing http://www.boostpro.com