From 2ef5200a6fb7311074904a1b4bf7ce750618a068 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Thu, 14 Dec 2023 15:26:42 +0000
Subject: [PATCH] libstdc++: Fix %S format of duration with floating-point rep
I got the order of arguments to std::format_to wrong. It was in a
discarded statement, for a case which wasn't being tested.
libstdc++-v3/ChangeLog:
* include/bits/chrono_io.h (__formatter_chrono::_M_S): Fix order
of arguments to std::format_to.
* testsuite/20_util/duration/io.cc: Test subsecond duration with
floating-point rep.
---
libstdc++-v3/include/bits/chrono_io.h | 2 +-
libstdc++-v3/testsuite/20_util/duration/io.cc | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/libstdc++-v3/include/bits/chrono_io.h b/libstdc++-v3/include/bits/chrono_io.h
index bcd76e4ab7b0..c30451651ea3 100644
--- a/libstdc++-v3/include/bits/chrono_io.h
+++ b/libstdc++-v3/include/bits/chrono_io.h
@@ -1137,7 +1137,7 @@ namespace __format
using rep = typename decltype(__ss)::rep;
if constexpr (is_floating_point_v<rep>)
{
- __out = std::format_to(__loc, std::move(__out),
+ __out = std::format_to(std::move(__out), __loc,
_GLIBCXX_WIDEN("{:.{}Lg}"),
__ss.count(),
__hms.fractional_width);
diff --git a/libstdc++-v3/testsuite/20_util/duration/io.cc b/libstdc++-v3/testsuite/20_util/duration/io.cc
index d2b9de73f83a..0582c0075a56 100644
--- a/libstdc++-v3/testsuite/20_util/duration/io.cc
+++ b/libstdc++-v3/testsuite/20_util/duration/io.cc
@@ -95,6 +95,10 @@ test_format()
"required by the chrono-specs") != s.npos);
}
}
+
+ std::chrono::duration<float, std::milli> d{0.5};
+ s = std::format("{}", d);
+ VERIFY( s == "0.5ms" );
}
void
--
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