https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87844
Bug ID: 87844
Summary: ICE in tsubst_copy using non-constant expression as a
non-type template argument
Product: gcc
Version: 8.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: curlypaul924 at gmail dot com
Target Milestone: ---
The following code causes ICE in every version I tried from 4.9.0 through 8.2,
as well as trunk:
struct C {
static constexpr bool call(bool) { return true; }
};
template<bool b>
struct B {};
auto foo(bool b) {
auto f = [](auto c) -> B<decltype(c)::call(b)> { };
f(C());
}
int main() {
foo(true);
}
Compile with either -std=c++14 or -std=c++17.
Clang (I believe correctly) rejects this code with "non-type template argument
is not a constant expression".
