https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67225
Bug ID: 67225
Summary: [concepts] Expression constraint with a constrained
result turns off access checking
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Keywords: accepts-invalid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ville.voutilainen at gmail dot com
CC: andrew.n.sutton at gmail dot com, eric.niebler at gmail dot
com,
jason at redhat dot com
Target Milestone: ---
Test, which compiles successfully but probably shouldn't:
template <class T, class U>
concept bool Same()
{
return true;
}
template <class T> struct WrapT {T t;};
template <class T>
concept bool Destructible()
{
return requires(T t, const T ct, WrapT<T>& wt)
{
{wt.~WrapT()} noexcept;
{&t} -> Same<T*>; // #1
//{&t} -> T*; // #2
};
}
template <Destructible T>
void f() {}
struct Y {private: ~Y();};
int main()
{
f<Y>();
}
If #1 is commented out, f<Y>() will correctly fail. Whether #2
is present doesn't matter. If the destructor of Y is deleted,
the presence of #1 doesn't matter and f<Y>() is rejected.
