changed locale retrieval to minimize the risk of unwanted accidental refactoring

This commit is contained in:
Pavel Novikov 2021-11-07 21:55:06 +03:00
parent 0b843af56b
commit 2087778ec4
No known key found for this signature in database
GPG Key ID: AEC4E958FA860F27

View File

@ -961,6 +961,16 @@ OutputIt format_duration_unit(OutputIt out) {
return out;
}
template <typename F>
auto with_locale(bool localized, locale_ref loc_ref, F&& f)
-> decltype(f(std::locale{})) {
if (localized) return f(loc_ref.template get<std::locale>());
// in contrast to the case above, classic locale is returned by reference
// without introducing a temporary object
// (locale copy ctor & dtor are relatively expensive)
return f(get_classic_locale());
}
template <typename FormatContext, typename OutputIt, typename Rep,
typename Period>
struct chrono_formatter {
@ -1062,14 +1072,11 @@ struct chrono_formatter {
void format_localized(const tm& time, char format, char modifier = 0) {
if (isnan(val)) return write_nan();
if (localized) {
out = detail::write<char_type>(
out, time, context.locale().template get<std::locale>(), format,
modifier);
} else {
out = detail::write<char_type>(out, time, get_classic_locale(), format,
modifier);
}
with_locale(localized, context.locale(),
[this, &time, format, modifier](const std::locale& loc) {
out = detail::write<char_type>(out, time, loc, format,
modifier);
});
}
void on_text(const char_type* begin, const char_type* end) {
@ -1234,13 +1241,13 @@ template <typename Char> struct formatter<weekday, Char> {
template <typename FormatContext>
auto format(weekday wd, FormatContext& ctx) const -> decltype(ctx.out()) {
auto time = std::tm();
time.tm_wday = static_cast<int>(wd.c_encoding());
if (localized)
return detail::write<Char>(ctx.out(), time,
ctx.locale().template get<std::locale>(), 'a');
return detail::write<Char>(ctx.out(), time, detail::get_classic_locale(),
'a');
auto out = ctx.out();
return detail::with_locale(
localized, ctx.locale(), [&out, wd](const std::locale& loc) {
auto time = std::tm();
time.tm_wday = static_cast<int>(wd.c_encoding());
return detail::write<Char>(out, time, loc, 'a');
});
}
};
@ -1855,10 +1862,11 @@ template <typename Char> struct formatter<std::tm, Char> {
template <typename FormatContext>
auto format(const std::tm& tm, FormatContext& ctx) const
-> decltype(ctx.out()) {
if (const auto& loc_ref = ctx.locale())
return this->do_format(ctx.out(), tm,
loc_ref.template get<std::locale>());
return this->do_format(ctx.out(), tm, detail::get_classic_locale());
auto out = ctx.out();
return detail::with_locale(static_cast<bool>(ctx.locale()), ctx.locale(),
[this, &out, &tm](const std::locale& loc) {
return do_format(out, tm, loc);
});
}
};