https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104094
Bug ID: 104094
Summary: Alias template shown in diagnostic with wrong template
parameter name
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
Target Milestone: ---
template<typename> struct trait;
template<typename A> struct trait { using type = A; };
template<typename B> struct cond { static constexpr bool value = true; };
template<bool> struct enable_if { using type = bool; };
template<> struct enable_if<false> { };
template<typename C>
class pair
{
template<typename D>
using constraint = cond<trait<D>>;
template<typename E, typename enable_if<constraint<E>::value>::type = true>
pair(E&&) { }
};
pair<int> p(1);
GCC prints:
name.C:18:14: error: 'pair<C>::pair(E&&) [with E = int; typename
enable_if<cond<trait<D> >::value>::type <anonymous> = true; C = int]' is
private within this context
18 | pair<int> p(1);
| ^
name.C:15:5: note: declared private here
15 | pair(E&&) { }
| ^~~~
Why does it show cond<trait<D>> in the error? There is no D in that
constructor's parameter list, and D is not explained in the [with ...] template
arg list.
I think it should be shown as constraint<E> or as cond<trait<E>>, but showing D
is just confusing.
