https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70845
Ville Voutilainen <ville.voutilainen at gmail dot com> changed:
What |Removed |Added
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CC| |ville.voutilainen at gmail dot
com
--- Comment #6 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
Here's a test snippet without library types. Clang accepts the code, gcc
rejects it.
template <class T>
struct holder
{
T t;
};
template <class... Args>
struct tuple_holder : holder<Args...>
{
tuple_holder(Args&&... args) : holder<Args>{static_cast<Args&&>(args)}...
{}
tuple_holder(const tuple_holder&) = default;
tuple_holder(tuple_holder&&) = default;
};
template <class T, class U>
struct my_pair
{
template <class... Args>
my_pair(tuple_holder<Args...>) {}
my_pair(const my_pair&) = default;
};
template <class T, class U>
struct my_real_pair : my_pair<T, U>
{
using my_pair<T, U>::my_pair;
};
int main()
{
my_real_pair<int, float>(tuple_holder<int&&>(1));
}
prog.cc: In constructor 'my_real_pair<int,
float>::my_real_pair(tuple_holder<Args ...>) [with Args = {int&&}]':
prog.cc:26:26: error: use of deleted function
'tuple_holder<Args>::tuple_holder(const tuple_holder<Args>&) [with Args =
{int&&}]'
using my_pair<T, U>::my_pair;
^~~~~~~
prog.cc:11:5: note: 'tuple_holder<Args>::tuple_holder(const
tuple_holder<Args>&) [with Args = {int&&}]' is implicitly deleted because the
default definition would be ill-formed:
tuple_holder(const tuple_holder&) = default;
^~~~~~~~~~~~
prog.cc:11:5: error: use of deleted function 'holder<int&&>::holder(const
holder<int&&>&)'
prog.cc:2:8: note: 'holder<int&&>::holder(const holder<int&&>&)' is implicitly
deleted because the default definition would be ill-formed:
struct holder
^~~~~~
prog.cc:2:8: error: copying non-static data member 'int&& holder<int&&>::t' of
rvalue reference type
prog.cc: In function 'int main()':
prog.cc:31:52: note: synthesized method 'my_real_pair<int,
float>::my_real_pair(tuple_holder<Args ...>) [with Args = {int&&}]' first
required here
my_real_pair<int, float>(tuple_holder<int&&>(1));
^
