https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94062
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|libstdc++ |c++
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reduced to remove any libstdc++ code:
template<typename T> T&& forward(T& t) { return static_cast<T&&>(t); }
template<typename T>
struct tuple : T
{
template<typename U>
tuple(U&& u)
: T(forward<U>(u))
{ }
};
struct Bar1
{
Bar1(const Bar1&) = delete;
Bar1(Bar1&&) = delete;
};
struct Foo1
{
operator Bar1() const;
};
int main()
{
tuple<Bar1> t{ Foo1{} };
}
With -std=c++17:
94062.cc: In instantiation of 'tuple<T>::tuple(U&&) [with U = Foo1; T = Bar1]':
94062.cc:25:25: required from here
94062.cc:8:24: error: use of deleted function 'Bar1::Bar1(Bar1&&)'
8 | : T(forward<U>(u))
| ^
94062.cc:15:5: note: declared here
15 | Bar1(Bar1&&) = delete;
| ^~~~
EDG also rejects it:
"94062.cc", line 8: error: function "Bar1::Bar1(Bar1 &&)" (declared at line 15)
cannot be referenced -- it is a deleted function
: T(forward<U>(u))
^
detected during instantiation of "tuple<T>::tuple(U &&) [with T=Bar1,
U=Foo1]" at line 25
1 error detected in the compilation of "94062.cc".
But MSVC and Clang compile it in C++17 mode.
