struct Foo;template< typename T>class Bar{}template<>class Bar<  Foo >{     int returnsomething()     {           return 1;     }}template< typename T>auto getsomething() -> decltype( Bar< T >::returnsomething ) {   Bar< T > t;   return t.returnsomething();}main(){   cout << getsomething< Foo >() << endl;}

test.cc:30:32: error: invalid use of non-static member function 'int Bar<Foo>::returnsomething()'test.cc:30:32: error: no matching function for call to 'getsomething()'

auto getsomething() -> decltype( Bar< T >::returnsomething )

auto getsomething() -> decltype( Bar< T >().returnsomething() )

Quote:Original post by u
Tried this on my GCC, got this:

test.cc:30:32: error: invalid use of non-static member function 'int Bar<Foo>::returnsomething()'test.cc:30:32: error: no matching function for call to 'getsomething()'

Changed this line:

auto getsomething() -> decltype( Bar< T >::returnsomething )

to:

auto getsomething() -> decltype( Bar< T >().returnsomething() )

and it compiles fine. Proper error message FTW.