[Bug libstdc++/127220] : clang rejects every dynamic width or precision ("{:{}}") in C++26 mode: __check_dynamic_spec is instantiated before its definition

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127220

--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The patch is an ABI break, isn't it? That's not acceptable. Even without the
new member, the change is quite invasive and makes the code less clear and less
maintainable - I don't like it.

The clang bug has been causing problems for years, they really need to fix it.