https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102000
Bug ID: 102000
Summary: Defaulted consteval default constructor that performs
no initialization is not rejected
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: accepts-invalid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: johelegp at gmail dot com
CC: johelegp at gmail dot com
Target Milestone: ---
See https://godbolt.org/z/Te3nY7YeW and discussion at
https://cpplang.slack.com/archives/C21PKDHSL/p1629467874085000.
```C++
struct X{
int i;
consteval X() = default;
};
constexpr void f() {
[[maybe_unused]] X x_f;
}
int main () {
[[maybe_unused]] X x_main;
[]() consteval { f(); }();
}
```
```
An immediate invocation shall be a constant expression. --
https://eel.is/c++draft/expr.const#13.sentence-3
Lots of wording in between...
2 A variable or temporary object o is constant-initialized if
(2.1) either it has an initializer or its default-initialization results in
some initialization being performed, and
-- https://eel.is/c++draft/expr.const#2
7 To default-initialize an object of type T means:
(7.3) Otherwise, no initialization is performed.
-- https://eel.is/c++draft/dcl.init.general#7
```
```
[W]hether it's defaulted or not, `i` is uninitialized so it should reject both.
```
