https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110739
--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Tomasz Kaminski <tkami...@gcc.gnu.org>: https://gcc.gnu.org/g:caac9489f62221da083684456c7c7ceca7425493 commit r16-1712-gcaac9489f62221da083684456c7c7ceca7425493 Author: Tomasz KamiÅski <tkami...@redhat.com> Date: Wed Jun 25 16:58:31 2025 +0200 libstdc++: Lift chrono localized formatting to main chrono format loop [PR110739] This patch extract calls to _M_locale_fmt and construction of the struct tm, from the functions dedicated to each specifier, to main format loop in _M_format_to functions. This removes duplicated code repeated for specifiers. To allow _M_locale_fmt to only be called if localized formatting is enabled ('L' is present in chrono-format-spec), we provide a implementations for locale specific specifiers (%c, %r, %x, %X) that produces the same result as locale::classic(): * %c is implemented as separate _M_c method * %r is implemented as separate _M_r method * %x is implemented together with %D, as they provide same behavior, * %X is implemented together with %R as _M_R_X, as both of them do not include subseconds. The handling of subseconds was also extracted to _M_subsecs function that is used by _M_S and _M_T specifier. The _M_T is now implemented in terms of _M_R_X (printing time without subseconds) and _M_subs. The __mod parameter responsible for triggering localized formatting was removed from methods handling most of specifiers, except: * _M_S (for %S) for which it determines if subseconds should be included, * _M_z (for %z) for which it determines if ':' is used as separator. PR libstdc++/110739 libstdc++-v3/ChangeLog: * include/bits/chrono_io.h (__formatter_chrono::_M_use_locale_fmt): Define. (__formatter_chrono::_M_locale_fmt): Moved to front of the class. (__formatter_chrono::_M_format_to): Construct and initialize struct tm and call _M_locale_fmt if needed. (__formatter_chrono::_M_c_r_x_X): Split into separate methods. (__formatter_chrono::_M_c, __formatter_chrono::_M_r): Define. (__formatter_chrono::_M_D): Renamed to _M_D_x. (__formatter_chrono::_M_D_x): Renamed from _M_D. (__formatter_chrono::_M_R_T): Split into _M_R_X and _M_T. (__formatter_chrono::_M_R_X): Extracted from _M_R_T. (__formatter_chrono::_M_T): Define in terms of _M_R_X and _M_subsecs. (__formatter_chrono::_M_subsecs): Extracted from _M_S. (__formatter_chrono::_M_S): Replaced __mod with __subs argument, removed _M_locale_fmt call, and delegate to _M_subsecs. (__formatter_chrono::_M_C_y_Y, __formatter_chrono::_M_d_e) (__formatter_chrono::_M_H_I, __formatter_chrono::_M_m) (__formatter_chrono::_M_u_w, __formatter_chrono::_M_U_V_W): Remove __mod argument and call to _M_locale_fmt. Reviewed-by: Jonathan Wakely <jwak...@redhat.com> Signed-off-by: Tomasz KamiÅski <tkami...@redhat.com>
