https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102050
Bug ID: 102050
Summary: Nonempty list-initialization rejects constructor with
defaulted std::initializer_list
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: johelegp at gmail dot com
CC: johelegp at gmail dot com
Target Milestone: ---
See https://godbolt.org/z/5PGza1o8e.
```C++
#include <initializer_list>
struct S { S( std::initializer_list<int> = {} ) {} };
int main() { S{0}; }
```
```
<source>: In function 'int main()':
<source>:3:17: error: no matching function for call to 'S::S(<brace-enclosed
initializer list>)'
3 | int main() { S{0}; }
| ^
<source>:2:12: note: candidate: 'S::S(std::initializer_list<int>)'
2 | struct S { S( std::initializer_list<int> = {} ) {} };
| ^
<source>:2:15: note: no known conversion for argument 1 from 'int' to
'std::initializer_list<int>'
2 | struct S { S( std::initializer_list<int> = {} ) {} };
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
<source>:2:8: note: candidate: 'constexpr S::S(const S&)'
2 | struct S { S( std::initializer_list<int> = {} ) {} };
| ^
<source>:2:8: note: no known conversion for argument 1 from 'int' to 'const
S&'
<source>:2:8: note: candidate: 'constexpr S::S(S&&)'
<source>:2:8: note: no known conversion for argument 1 from 'int' to 'S&&'
Compiler returned: 1
```
This came up at https://cpplang.slack.com/archives/C2SLQATS9/p1629835850325200.
