Re: [Boost-users] [Concepts & EnableIf] Is void special?

Hi All Ok, I should probably have started this thread with this self contained code example. What's wrong with this? #include <vector> #include #include #include #include template <typename T> BOOST_CONCEPT_REQUIRES( (( boost::SinglePassRangeConcept<T> )), // ( void )) ( typename boost::enable_if, void>::type )) f( const T & ) { } int main( ) { std::vector<int> v; f( v ); } g++ -c -o enable_if.o enable_if.cpp enable_if.cpp: In function ‘int main()’: enable_if.cpp:17: error: no matching function for call to ‘f(std::vector&)’ If I comment out the enable_if line and comment in the void line it's fine. TIA, Rob.