https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84692
Bug ID: 84692
Summary: Class template argument deduction ICE for template's
member template
Product: gcc
Version: 8.0.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: colu...@gmx-topmail.de
Target Milestone: ---
template <typename... Ts>
struct X {
template <typename U>
struct Y {
Y(U, Ts const&... );
};
friend void begin(X) {
Y{0, Ts{}...};
}
};
int main() {
begin(X<int>{});
}
---------------
prog.cc: In substitution of 'template<class Iter> iterator(Iter, const Ts&
...)-> incrementing_range<Ts ...>::iterator<Iter> [with Iter = 128]':
prog.cc:9:7: required from 'void begin(incrementing_range<int>)'
prog.cc:14:34: required from here
prog.cc:9:7: internal compiler error: in tsubst, at cp/pt.c:13992
iterator{0, Ts{}...};
^~~~~~~~
---------------
I can't reduce this any further.
Oddly, Clang claims this is ill-formed, while I reckon this should compile,
although I haven't delved into the wording to see what it mandates regarding
template members. Perhaps iterator is treated as the qualified-id X::Y, and the
compilers attempt to deduce Ts, which fails?
