https://gcc.gnu.org/bugzilla/show_bug.cgi?id=20906
--- Comment #5 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
With a slight change in the parse tree, we get a much better message.
prog.cc:3:38: error: wrong number of template arguments (0, should be 1)
template<int k> void foo<k>::pop(bar<>&, int) {}
^
prog.cc:1:22: note: provided for 'template<int <anonymous> > struct bar'
template<int> struct bar {};
^~~
prog.cc:3:22: error: prototype for 'void foo<i>::pop(int&, int)' does not match
any in class 'foo<i>'
template<int k> void foo<k>::pop(bar<>&, int) {}
^~~~~~
prog.cc:2:35: error: candidate is: void foo<i>::pop(bar<i>&, int)
template<int i> struct foo { void pop(bar<i>& b, int j); };
^~~
Comparing these two cases should point out at the solution.
