| Issue |
138775
|
| Summary |
various warnings incorrectly included in `-Wc++20-compat`
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
zygoloid
|
Example:
```c++
template<typename T> consteval T::type f();
```
... compiled with `-std=c++20 -Weverything` produces:
```
<source>:1:32: warning: use of implicit 'typename' is incompatible with C++ standards before C++20 [-Wc++20-compat]
1 | template<typename T> consteval T::type f();
| ^
<source>:1:22: warning: 'consteval' specifier is incompatible with C++ standards before C++20 [-Wc++20-compat]
1 | template<typename T> consteval T::type f();
| ^
```
This doesn't make any sense. `-Wc++XY-compat` is supposed to warn about compatibility issues that would arise when compiling with `-std=c++XY`. But that's not what these warnings are about at all!
These warnings should be in `-Wpre-c++20-compat`, because they warn about compatibility issues that would arise when compiling with standards earlier than `-std=c++20`. It'd be good to do a survey of other `-Wc++XY-compat` warnings too, to check for other places we might have got this wrong.
![]()
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
