Tested x86_64-linux. Pushed to trunk.
-- >8 --
When converting a chrono::duration<long double> to a result type with an
integer representation we should use chrono::round<_Duration> so that we
don't truncate towards zero. Rounding ensures that e.g. 0.001999s
becomes 2ms not 1ms.
We can also remove some redundant uses of chrono::duration_cast to
convert from seconds to _Duration, because the _Parser class template
requires _Duration type to be able to represent seconds without loss of
precision.
This also fixes a bug where no fractional part would be parsed for
chrono::duration<long double> because its period is ratio<1>. We should
also consider treat_as_floating_point<rep> when deciding whether to skip
reading a fractional part.
libstdc++-v3/ChangeLog:
PR libstdc++/114244
* include/bits/chrono_io.h (_Parser::operator()): Remove
redundant uses of duration_cast. Use chrono::round to convert
long double value to durations with integer representations.
Check represenation type when deciding whether to skip parsing
fractional seconds.
* testsuite/20_util/duration/114244.cc: New test.
* testsuite/20_util/duration/io.cc: Check that a floating-point
duration with ratio<1> precision can be parsed.
---
libstdc++-v3/include/bits/chrono_io.h | 18 ++++++----
.../testsuite/20_util/duration/114244.cc | 36 +++++++++++++++++++
libstdc++-v3/testsuite/20_util/duration/io.cc | 12 +++++++
3 files changed, 60 insertions(+), 6 deletions(-)
create mode 100644 libstdc++-v3/testsuite/20_util/duration/114244.cc
diff --git a/libstdc++-v3/include/bits/chrono_io.h
b/libstdc++-v3/include/bits/chrono_io.h
index 82f2d39ec44..b8f0657bee9 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -3113,6 +3113,9 @@ namespace __detail
unsigned __num = 0; // Non-zero for N modifier.
bool __is_flag = false; // True if we're processing a % flag.
+ constexpr bool __is_floating
+ = treat_as_floating_point_v<typename _Duration::rep>;
+
// If an out-of-range value is extracted (e.g. 61min for %M),
// do not set failbit immediately because we might not need it
// (e.g. parsing chrono::year doesn't care about invalid %M values).
@@ -3195,7 +3198,7 @@ namespace __detail
__d = day(__tm.tm_mday);
__h = hours(__tm.tm_hour);
__min = minutes(__tm.tm_min);
- __s = duration_cast<_Duration>(seconds(__tm.tm_sec));
+ __s = seconds(__tm.tm_sec);
}
}
__parts |= _ChronoParts::_DateTime;
@@ -3564,8 +3567,8 @@ namespace __detail
if (!__is_failed(__err))
__s = seconds(__tm.tm_sec);
}
- else if constexpr (ratio_equal_v<typename _Duration::period,
- ratio<1>>)
+ else if constexpr (_Duration::period::den == 1
+ && !__is_floating)
{
auto __val = __read_unsigned(__num ? __num : 2);
if (0 <= __val && __val <= 59) [[likely]]
@@ -3577,7 +3580,7 @@ namespace __detail
break;
}
}
- else
+ else // Read fractional seconds
{
basic_stringstream<_CharT> __buf;
auto __digit = _S_try_read_digit(__is, __err);
@@ -3626,7 +3629,10 @@ namespace __detail
else
{
duration<long double> __fs(__val);
- __s = duration_cast<_Duration>(__fs);
+ if constexpr (__is_floating)
+ __s = __fs;
+ else
+ __s = chrono::round<_Duration>(__fs);
}
}
}
@@ -3737,7 +3743,7 @@ namespace __detail
{
__h = hours(__tm.tm_hour);
__min = minutes(__tm.tm_min);
- __s = duration_cast<_Duration>(seconds(__tm.tm_sec));
+ __s = seconds(__tm.tm_sec);
}
}
__parts |= _ChronoParts::_TimeOfDay;
diff --git a/libstdc++-v3/testsuite/20_util/duration/114244.cc
b/libstdc++-v3/testsuite/20_util/duration/114244.cc
new file mode 100644
index 00000000000..55a7670522a
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/duration/114244.cc
@@ -0,0 +1,36 @@
+// { dg-do run { target c++20 } }
+// { dg-timeout-factor 2 }
+// { dg-require-namedlocale "en_US.ISO8859-1" }
+
+// PR libstdc++/114244 Need to use round when parsing fractional seconds
+
+#include <chrono>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test_pr114244()
+{
+ using namespace std::chrono;
+ seconds s;
+ milliseconds ms;
+ microseconds us;
+
+ std::istringstream is;
+
+ is.clear();
+ is.str("0.002");
+ VERIFY( is >> parse("%S", ms) );
+ VERIFY( ms == 2ms ); // not 1ms
+
+ is.imbue(std::locale(ISO_8859(1,en_US)));
+ is.clear();
+ is.str("0.002");
+ VERIFY( is >> parse("%S", us) );
+ VERIFY( us == 2000us ); // not 1999us
+}
+
+int main()
+{
+ test_pr114244();
+}
diff --git a/libstdc++-v3/testsuite/20_util/duration/io.cc
b/libstdc++-v3/testsuite/20_util/duration/io.cc
index e141baf42dc..2f940ef86b7 100644
--- a/libstdc++-v3/testsuite/20_util/duration/io.cc
+++ b/libstdc++-v3/testsuite/20_util/duration/io.cc
@@ -200,6 +200,18 @@ test_parse()
VERIFY( is >> parse("%S", us) );
VERIFY( us == 976us );
VERIFY( is.get() == '5' );
+
+ is.clear();
+ is.str("0.5");
+ std::chrono::duration<double> ds;
+ VERIFY( is >> parse("%S", ds) );
+ VERIFY( ds == 0.5s );
+
+ is.clear();
+ is.str("0.125");
+ std::chrono::duration<double, std::milli> dms;
+ VERIFY( is >> parse("%S", dms) );
+ VERIFY( dms == 0.125s );
}
int main()
--
2.43.2
