https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123243
Bug ID: 123243
Summary: Diagnostics for virtual functions with requires
clauses are not very user-friendly
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: hewillk at gmail dot com
Target Milestone: ---
Consider:
https://godbolt.org/z/GxqffsePn
template<class T>
struct A {
class B {
virtual void f() requires true = 0;
};
};
Clang gives
<source>:4:31: error: virtual function cannot have a requires clause
4 | virtual void f() requires true = 0;
MSVC gives
example.cpp
<source>(4): error C7632: 'A<T>::B::f': a trailing requires clause is not
allowed on a virtual function
However, GCC gives
<source>:4:38: error: lvalue required as left operand of assignment
[-Wtemplate-body]
4 | virtual void f() requires true = 0;
It would be great if GCC could explicitly state, like others, "that virtual
functions cannot have a requires clause"; the current diagnostic messages are
vague
