https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58589
Jonathan Wakely <redi at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jan Kratochvil from comment #0)
> #include <unordered_map>
> #include <memory>
> class X {
> public:
> int a,&b; /* the reference disables default copy constructor */
What has the copy constructor got to do with anything?
std::unique_ptr<X> never tries to copy an X
Reduced:
template<class T>
struct impl
{
T t;
impl& operator=(const impl& i) { t = i.t; return *this; }
};
template<class T>
struct unordered_map
{
impl<T> m_impl;
};
struct unique_ptr {
unique_ptr& operator=(const unique_ptr&) = delete;
};
struct Y {
unordered_map<unique_ptr> x;
};
int main() {
Y a;
a = a;
}
j.cc: In instantiation of ‘impl<T>& impl<T>::operator=(const impl<T>&) [with T
= unique_ptr]’:
j.cc:10:8: required from here
j.cc:6:38: error: use of deleted function ‘unique_ptr&
unique_ptr::operator=(const unique_ptr&)’
impl& operator=(const impl& i) { t = i.t; return *this; }
~~^~~~~
j.cc:16:15: note: declared here
unique_ptr& operator=(const unique_ptr&) = delete;
^~~~~~~~
There's nothing showing the location of the "a = a" expression that requires
the deleted Y::operator=(const Y&).
