https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83870
Bug ID: 83870
Summary: template parameter pack followed by another template
parameter does not error when following parameter can
not be deduced
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: smw at gcc dot gnu.org
Target Milestone: ---
[temp.param]/11 tells us "A template parameter pack of a function template
shall not be followed by another template parameter unless that template
parameter can be deduced from the parameter-type-list of the function template
or has a default argument" and then it goes on to give us a couple of handy
examples.
// U can be neither deduced from the parameter-type-list nor specified
template<class... T, class... U> void f() { } // error
template<class... T, class U> void g() { } // error
// the above is cut-n-paste from n3690, and for a complete program:
int
main()
{
f();
}
MSVC19 and ICC18 issue diagnostics. GCC8 silently produces an executable.
