https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90287
Bug ID: 90287
Summary: [concepts] bogus error on overload failure inside
requires-expression
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redbeard0531 at gmail dot com
Target Milestone: ---
https://godbolt.org/z/30Cf6s
#include <string>
template <typename T, typename U>
constexpr inline bool isAddable = requires(const T& lhs, const U& rhs) {
lhs + rhs;
};
auto x = isAddable<int, std::string>;
<source>: In instantiation of 'constexpr const bool isAddable<int,
std::__cxx11::basic_string<char> >':
<source>:13:10: required from here
<source>:10:10: error: no match for 'operator+' (operand types are 'const int'
and 'const std::__cxx11::basic_string<char>')
10 | lhs + rhs ;
| ~~~~^~~~~
[snip rest of wall-o-errors]
If I make isAddable a concept, it correctly evaluates to false, but I would
expect requires-expressions to also work when assigned to a constexpr bool.
