https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92523
Bug ID: 92523
Summary: Unhelpful error messages when requires-clause contains
function call
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: boostcpp at gmail dot com
Target Milestone: ---
Following code produce unhelpful error messages:
constexpr bool f() { return true ; }
template < typename T >
requires f()
void g(){}
https://wandbox.org/permlink/bH2Eo2aTC2JeueZt
prog.cc:4:14: error: constraint expression does not have type 'bool'
4 | requires f()
| ^
prog.cc:4:16: error: expected unqualified-id before ')' token
4 | requires f()
| ^
If the requires-clause was like this:
requires 2 + 2 == 5
It does produce helpful error messages which clearly show what's wrong here.
https://wandbox.org/permlink/xIMiqWVcVrDkMU55
prog.cc:4:14: error: constraint expression does not have type 'bool'
4 | requires 2 + 2 == 5
| ^
prog.cc:4:16: error: expression after 'requires' must be enclosed in
parentheses
4 | requires 2 + 2 == 5
| ~~^~~~~~~~
| ( )
function call expression inside the requires-clause should produce helpful
messages like it already does in other expressions.
