https://gcc.gnu.org/g:01eef394913bd5d682dc5eec9c45e87dabf4d8a3
commit r17-2051-g01eef394913bd5d682dc5eec9c45e87dabf4d8a3 Author: Anlai Lu <[email protected]> Date: Tue Jun 30 12:49:02 2026 +0000 libstdc++: Add stream state tests for chrono operator<< Add tests covering formatted output function semantics for the chrono operator<< overloads. These verify that the new stack-buffer implementation correctly preserves sentry construction (badbit check and tied stream flush), width/fill padding with all three alignment modes (right, left, internal), width reset after each output, and locale-aware output. A weekday_indexed content test and a wchar_t smoke test are included. libstdc++-v3/ChangeLog: * testsuite/std/time/ostream_insert.cc: New test. Reviewed-by: Jonathan Wakely <[email protected]> Reviewed-by: Tomasz Kamiński <[email protected]> Signed-off-by: Anlai Lu <[email protected]> Diff: --- libstdc++-v3/testsuite/std/time/ostream_insert.cc | 183 ++++++++++++++++++++++ 1 file changed, 183 insertions(+) diff --git a/libstdc++-v3/testsuite/std/time/ostream_insert.cc b/libstdc++-v3/testsuite/std/time/ostream_insert.cc new file mode 100644 index 000000000000..7d872aa8f9fe --- /dev/null +++ b/libstdc++-v3/testsuite/std/time/ostream_insert.cc @@ -0,0 +1,183 @@ +// { dg-do run { target c++20 } } + +// Test stream state semantics for chrono operator<< +#include <chrono> +#include <format> +#include <iomanip> +#include <sstream> +#include <testsuite_hooks.h> + +bool +check_prefix(std::string_view s, size_t n, char c) +{ + for (char v : s) + if (v != c) + return !n; + else if (!n) + return false; + else + --n; + return false; +} + +void +test_sentry_badbit() +{ + using namespace std::chrono; + std::ostringstream os; + os.setstate(std::ios::badbit); + VERIFY( !os.good() ); + os << sys_time<seconds>{1'700'000'000s}; + VERIFY( os.bad() ); + VERIFY( os.str().empty() ); +} + +void +test_sentry_tied() +{ + using namespace std::chrono; + struct testbuf : std::streambuf + { bool flushed = false; int sync() override { flushed = true; return 0; } }; + testbuf tied_buf; std::ostream tied(&tied_buf); std::ostringstream os; + os.tie(&tied); + os << sys_time<seconds>{1'700'000'000s}; + VERIFY( tied_buf.flushed == true ); +} + +void +test_width_fill() +{ + using namespace std::chrono; + std::ostringstream os; + os << std::setw(30) << std::setfill('*') << sys_time<seconds>{1'700'000'000s}; + auto s = os.view(); + VERIFY( s.size() == 30 ); + VERIFY( check_prefix(s, 11, '*') ); + VERIFY( s.substr(11) == "2023-11-14 22:13:20" ); + VERIFY( os.width() == 0 ); +} + +void +test_width_left() +{ + using namespace std::chrono; + std::ostringstream os; + os << std::setw(30) << std::left << std::setfill('.') << sys_time<seconds>{1'700'000'000s}; + auto s = os.view(); + VERIFY( s.size() == 30 ); + VERIFY( s.find("2023-11-14") == 0 ); + VERIFY( s.back() == '.' ); + VERIFY( os.width() == 0 ); +} + +void +test_width_internal() +{ + using namespace std::chrono; + std::ostringstream os; + os << std::setw(30) << std::internal << std::setfill('_') << day(15); + auto s = os.view(); + VERIFY( s.size() == 30 ); + VERIFY( check_prefix(s, 28, '_') ); + VERIFY( s.substr(28) == "15" ); + VERIFY( os.width() == 0 ); +} + +void +test_width_reset() +{ + using namespace std::chrono; + std::ostringstream os; + os << std::setw(20) << sys_time<seconds>{1'700'000'000s}; + VERIFY( os.width() == 0 ); + os << hh_mm_ss{seconds(45296)}; + VERIFY( os.width() == 0 ); + os << std::setw(15) << day(15); + VERIFY( os.width() == 0 ); +} + +void +test_width_zero() +{ + using namespace std::chrono; + std::ostringstream os; + os << std::setw(0) << sys_time<seconds>{1'700'000'000s}; + auto s = os.view(); + VERIFY( s.find("2023-11-14") != std::string::npos ); + VERIFY( s.size() < 20 ); + VERIFY( os.width() == 0 ); +} + +void +test_multiple_chrono_types() +{ + using namespace std::chrono; + std::ostringstream os; + os << std::setw(25) << std::setfill('-') << sys_time<seconds>{1'700'000'000s}; + VERIFY( check_prefix(os.view(), 6, '-') ); + VERIFY( os.width() == 0 ); + os << std::setw(15) << hh_mm_ss{seconds(45296)}; + VERIFY( check_prefix(os.view().substr(25), 7, '-') ); + VERIFY( os.width() == 0 ); + os << std::setw(10) << day(15); + VERIFY( check_prefix(os.view().substr(40), 8, '-') ); + VERIFY( os.width() == 0 ); + os << std::setw(10) << month(7); + VERIFY( check_prefix(os.view().substr(50), 7, '-') ); + VERIFY( os.width() == 0 ); + os << std::setw(10) << year(2026); + VERIFY( check_prefix(os.view().substr(60), 6, '-') ); + VERIFY( os.width() == 0 ); + os << std::setw(12) << Monday; + VERIFY( check_prefix(os.view().substr(70), 9, '-') ); + VERIFY( os.width() == 0 ); +} + +void +test_locale_aware() +{ + using namespace std::chrono; + std::ostringstream os; + os.imbue(std::locale::classic()); + os << std::setw(12) << Monday; + auto s = os.view(); + VERIFY( s.size() >= 12 ); + VERIFY( os.width() == 0 ); +} + +void +test_wchar_t() +{ + using namespace std::chrono; + std::wostringstream wos; + wos << std::chrono::sys_time<std::chrono::seconds>{1'700'000'000s}; + VERIFY( wos.view() == L"2023-11-14 22:13:20" ); +} + +void +test_weekday_indexed() +{ + using namespace std::chrono; + std::ostringstream os; + os << Monday[1]; + VERIFY( os.view() == "Mon[1]" ); + os.str(""); + os << Monday[6]; // invalid index + VERIFY( os.view().find("Mon[") != std::string::npos ); +} + +int +main() +{ + test_sentry_badbit(); + test_sentry_tied(); + test_width_fill(); + test_width_left(); + test_width_internal(); + test_width_reset(); + test_width_zero(); + test_multiple_chrono_types(); + test_locale_aware(); + test_wchar_t(); + test_weekday_indexed(); +}
