https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115471
Bug ID: 115471
Summary: Fail to capture (with initializer) constant bit-fields
by reference in lambda expression
Product: gcc
Version: 14.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: fchelnokov at gmail dot com
Target Milestone: ---
This program
```
struct U {
int i : 4;
};
using CU = const U;
auto lm = [&y = CU{5}.i]() { return y; };
```
is accepted by Clang and MSVC, and it shall be because when initializing a
const reference from a bit-field, a temporary is created (its type is the type
of the bit-field), copy initialized with the value of the bit-field, and the
reference is bound to that temporary.
But GCC fails here with the
error: cannot capture 'CU{5}.U::i' by reference
Online demo: https://gcc.godbolt.org/z/qnToW4qfY
Related discussion: https://stackoverflow.com/q/78611419/7325599
