https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125333
Bug ID: 125333
Summary: Pack expansion of using-declaration of conversion
operator 'taints' the type pack
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mital at mitalashok dot co.uk
Target Milestone: ---
<https://godbolt.org/z/Wxc5E3fET>:
template<typename... T>
struct X {};
template <typename U>
struct Y {
operator U();
};
template <typename... V>
struct Z : Y<V>... {
using Y<V>::operator V...;
X<V...> x;
};
Z<int, double> z;
Output:
example.cpp: In instantiation of 'struct Z<operator int, operator double>':
example.cpp16:16: required from here
16 | Z<int, double> z;
| ^
example.cpp:13:13: error: type/value mismatch at argument 1 in template
parameter list for 'template<class ... T> struct X'
13 | X<V...> x;
| ^
example.cpp:13:13: note: expected a type, got 'operator int'
example.cpp:13:13: error: type/value mismatch at argument 1 in template
parameter list for 'template<class ... T> struct X'
example.cpp:13:13: note: expected a type, got 'operator double'
It seems to have turned T -> operator T?
Potentially related: Bug 108090 and Bug 125284
