<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/88089>88089</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Diagnostics for P2266 (C++23) are poor
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          tiagomacarios
      </td>
    </tr>
</table>

<pre>
    The diagnostics for the following code are very poor:
https://godbolt.org/z/5nv9dcr14
```c++
struct M {
 M();
    M(M&);
};

struct S {
    int m1;
    M m2;
};

S fun() {
    S s{};
    return s;
}
```

clang's output:
```
<source>:15:12: error: no viable conversion from 'S' to 'int'
   15 |     return s;
      | ^
```

gcc's output:
```
<source>: In function 'S fun()':
<source>:15:12: error: use of deleted function 'S::S(S&&)'
 15 |     return s;
      |            ^
<source>:8:8: note: 'S::S(S&&)' is implicitly deleted because the default definition would be ill-formed:
 8 | struct S {
      |        ^
<source>: At global scope:
<source>:8:8: error: cannot bind non-const lvalue reference of type 'M&' to an rvalue of type 'M'
<source>:5:7: note:   initializing argument 1 of 'M::M(M&)'
    5 |     M(M&);
      |       ^~
<source>: In function 'S fun()':
<source>:15:12: note: use '-fdiagnostics-all-candidates' to display considered candidates
   15 | return s;
      |            ^
```
</pre>
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