Cold-Air-Networks/mirror-llvm-project
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions 7

[clang][NFC] Mark CWG2785 as implemented and add a test (#195547)

Browse source 
[CWG2785](https://wg21.link/cwg2785) clarifies that a
*requires-expression* is never type-dependent, it always has type
`bool`. That means that in a snippet like this:
```cpp
void g(void *);

template <typename T>
void f() {
  g(requires { T(); });
}
```
The call to `g` should be diagnosed as invalid (`bool` is not
convertible to `void *`) even if the template is never instantiated.
Clang does the right thing since version 10:
https://godbolt.org/z/s61rEbsfz
This commit is contained in:
Victor Chernyakin 2026-05-04 10:16:45 -07:00 committed by GitHub
parent 55124c4e60
commit 8a26ecc0b7
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
2 changed files with 14 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
clang/test/CXX/drs/cwg27xx.cpp
View file

@ -204,6 +204,19 @@ void g() {
} // namespace cwg2780
namespace cwg2785 { // cwg2785: 10
#if __cplusplus >= 202002L
void g(void *); // #cwg2785-g
template <typename T>
void f() {
g(requires { T(); });
// since-cxx20-error@-1 {{no matching function for call to 'g'}}
// since-cxx20-note@#cwg2785-g {{candidate function not viable: no known conversion from 'bool' to 'void *' for 1st argument}}
}
#endif
} // namespace cwg2785
namespace cwg2789 { // cwg2789: 18
#if __cplusplus >= 202302L
template <typename T = int>

2
clang/www/cxx_dr_status.html
View file

@ -19304,7 +19304,7 @@
<td>[<a href="https://wg21.link/temp.dep.expr">temp.dep.expr</a>]</td>
<td>CD7</td>
<td>Type-dependence of <I>requires-expression</I></td>
<td class="unknown" align="center">Unknown</td>
<td class="full" align="center">Clang 10</td>
</tr>
<tr class="open" id="2786">
<td><a href="https://cplusplus.github.io/CWG/issues/2786.html">2786</a></td>