https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120114
Bug ID: 120114
Summary: Format width is not correctly handled for chrono
formatting
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: tkaminsk at gcc dot gnu.org
Target Milestone: ---
Field width is not correctly computed when Unicode characters are included in
chrono-spec:
```
using namespace std::chrono_literals;
auto date = 2025y/std::chrono::May/05d;
auto res = std::format("{:+<13%F\U0001f921}", date);
// 2025-05-05🤡, should have 1 '+' of padding
std::cout << res << std::endl;
res = std::format("{:+<15%F\U0001f921}", date);
// 2025-05-05🤡+, should have 3 '+' of padding
std::cout << res << std::endl;
auto wres = std::format(L"{:+<13%F\U0001f921}", date);
// 2025-05-05🤡++, should have 1 '+' of padding
wres = std::format(L"{:+<15%F\U0001f921}", date);
// 2025-05-05🤡++++, should have 3 '+' of padding
```
See: https://godbolt.org/z/d3x5Gq83h
