[Bug libstdc++/103879] New: error: accessing value of variant::_Copy_ctor_base through a 'const variant' glvalue in a constant expression

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103879

            Bug ID: 103879
           Summary: error: accessing value of variant::_Copy_ctor_base
                    through a 'const variant<string>' glvalue in a
                    constant expression
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

From
https://stackoverflow.com/questions/70541636/stdvariant-of-stdstring-inside-any-class-in-constexpr-context-fails-to-compi

#include <string>
#include <variant>

struct S {
  std::variant<std::string> v;
};

constexpr int func() {
  S s{"str"};
  return 0;
}

constexpr int x = func();

I think this should be well-formed.