https://gcc.gnu.org/g:7206d4b9f95a48ab11cebc51bb10a67964a129f3
commit r13-10318-g7206d4b9f95a48ab11cebc51bb10a67964a129f3 Author: Jonathan Wakely <[email protected]> Date: Thu May 15 19:32:01 2025 +0100 libstdc++: Fix std::format of chrono::local_days with {} [PR120293] Formatting of chrono::local_days with an empty chrono-specs should be equivalent to inserting it into an ostream, which should use the overload for inserting chrono::sys_days into an ostream. The implementation of empty chrono-specs in _M_format_to_ostream takes some short cuts, and that wasn't being done correctly for chrono::local_days. libstdc++-v3/ChangeLog: PR libstdc++/120293 * include/bits/chrono_io.h (_M_format_to_ostream): Add special case for local_time convertible to local_days. * testsuite/std/time/clock/local/io.cc: Check formatting of chrono::local_days. Reviewed-by: Tomasz Kamiński <[email protected]> (cherry picked from commit 1ed7585bf60ba9940ca5dc6d2c72dba86eea7b4d) Diff: --- libstdc++-v3/include/bits/chrono_io.h | 3 +++ libstdc++-v3/testsuite/std/time/clock/local/io.cc | 6 ++++++ 2 files changed, 9 insertions(+) diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h index 63c0a8949bcd..2a7527cae2d6 100644 --- a/libstdc++-v3/include/bits/chrono_io.h +++ b/libstdc++-v3/include/bits/chrono_io.h @@ -728,6 +728,9 @@ namespace __format // sys_time with period greater or equal to days: if constexpr (is_convertible_v<_Tp, chrono::sys_days>) __os << _S_date(__t); + // Or a local_time with period greater or equal to days: + else if constexpr (is_convertible_v<_Tp, chrono::local_days>) + __os << _S_date(__t); else // Or it's formatted as "{:L%F %T}": { auto __days = chrono::floor<chrono::days>(__t); diff --git a/libstdc++-v3/testsuite/std/time/clock/local/io.cc b/libstdc++-v3/testsuite/std/time/clock/local/io.cc index 33eb9f08e806..85fd734fd634 100644 --- a/libstdc++-v3/testsuite/std/time/clock/local/io.cc +++ b/libstdc++-v3/testsuite/std/time/clock/local/io.cc @@ -87,6 +87,12 @@ test_format() s = std::format("{:%Z %T %F %z %Ez}", ltf); __builtin_puts(s.c_str()); VERIFY( s == "FOO 20:22:02 2024-07-28 -0100 -01:00" ); + + s = std::format("{}", local_seconds{}); + VERIFY( s == "1970-01-01 00:00:00" ); + + s = std::format("{}", local_days{}); // PR libstdc++/120293 + VERIFY( s == "1970-01-01" ); } int main()
