[Bug c++/112642] ranges::fold_left tries to access inactive union member of string in constant expression

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112642

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|libstdc++                   |c++

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Or:

#include <string>

consteval void bar() {
    auto _ = [](std::string s) { return s; }({});
}

int main() {
    bar();    
}

Or:

#include <string>
constexpr auto foo(std::string init) { return init; }
constexpr auto bar() { return foo("").size(); }
constexpr auto i = bar();

Clang compiles both of these without problems (it can't compile anything using
""s in a constant expression, maybe due to
https://github.com/llvm/llvm-project/issues/68527)

So I am pretty sure this is a g++ front end bug.