https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91483
Bug ID: 91483
Summary: Poor diagnostic on trying to take constexpr reference
to non-static object
Product: gcc
Version: 9.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: barry.revzin at gmail dot com
Target Milestone: ---
Consider:
struct X {
int const& var;
};
void foo() {
constexpr int i = 42;
constexpr X x{i};
}
This is ill-formed because i doesn't have static storage duration. But the
error gcc provides is:
<source>: In function 'void foo()':
<source>:7:20: error: 'const X{i}' is not a constant expression
7 | constexpr X x{i};
| ^
It would be a lot nicer if the diagnostic here explained the reason that this
isn't a constant expression.
