https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120159
Bug ID: 120159
Summary: is_layout_compatible_v not exported in std module
Product: gcc
Version: 15.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: alberto.gcc.bugzilla at gmail dot com
Target Milestone: ---
Hello
It appears that is_layout_compatible_v, is_corresponding_member_v, and
is_pointer_interconvertible_with_class_v aren't exported by the std module.
In std.cc.in I can only find:
#if __cpp_lib_is_layout_compatible
using std::is_corresponding_member;
using std::is_layout_compatible;
#endif
#if __cpp_lib_is_pointer_interconvertible
using std::is_pointer_interconvertible_base_of;
using std::is_pointer_interconvertible_base_of_v;
using std::is_pointer_interconvertible_with_class;
#endif
As a consequence, the following program:
``` hello.cpp
import std;
struct A
{
double a;
};
struct B
{
double a;
};
static_assert(std::is_layout_compatible_v<A, B>);
static_assert(std::is_layout_compatible<A, B>::value); // passes
```
compiled with:
g++ -std=c++23 -fmodules -fsearch-include-path bits/std.cc hello.cpp -o
hello.out
fails:
hello.cpp:13:20: error: 'is_layout_compatible_v' is not a member of 'std'
13 | static_assert(std::is_layout_compatible_v<A, B>);
| ^~~~~~~~~~~~~~~~~~~~~~
Thank you
