https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112354
Bug ID: 112354
Summary: mismatched types 'B<T>' and 'B<int>&' for generic
lambda noexcept-specifier referencing enclosing
function parameter
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ed at catmur dot uk
Target Milestone: ---
Since 4.9.0,
template<class>
struct B {
B();
B(B const&);
};
template<class T> void g(B<T>, int);
auto f(B<int> x) {
return [](auto y) noexcept(noexcept(g(x, y))) {
return 1;
};
}
int i = f({})(0);
fails with:
<source>: In instantiation of 'f(B<int>)::<lambda(auto:1)> [with auto:1 =
int]':
<source>:12:14: required from here
12 | int i = f({})(0);
| ~~~~~^~~
<source>:8:42: error: no matching function for call to 'g(B<int>&&, int&)'
8 | return [](auto y) noexcept(noexcept(g(x, y))) {
| ~^~~~~~
<source>:6:24: note: candidate: 'template<class T> void g(B<T>, int)'
6 | template<class T> void g(B<T>, int);
| ^
<source>:6:24: note: template argument deduction/substitution failed:
<source>:8:42: note: mismatched types 'B<T>' and 'B<int>&'
8 | return [](auto y) noexcept(noexcept(g(x, y))) {
| ~^~~~~~
