This is a missing piece of the C++20 <chrono> header.
It would be good to move the code into the compiled library, so that we
don't need <sstream> in <chrono>. It could also use spanstream in C++20,
to avoid memory allocations. That can be changed at a later date.
libstdc++-v3/ChangeLog:
* include/std/chrono (__detail::__units_suffix_misc): New
helper function.
(__detail::__units_suffix): Likewise.
(chrono::operator<<(basic_ostream&, const duration&)): Define.
* testsuite/20_util/duration/io.cc: New test.
Tested powerpc64le-linux. Committed to trunk.
commit fcc13d6fc31441b5672b68a5e3b247687724218f
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Thu Oct 7 19:58:07 2021
libstdc++: Implement ostream insertion for chrono::duration
This is a missing piece of the C++20 <chrono> header.
It would be good to move the code into the compiled library, so that we
don't need <sstream> in <chrono>. It could also use spanstream in C++20,
to avoid memory allocations. That can be changed at a later date.
libstdc++-v3/ChangeLog:
* include/std/chrono (__detail::__units_suffix_misc): New
helper function.
(__detail::__units_suffix): Likewise.
(chrono::operator<<(basic_ostream&, const duration&)): Define.
* testsuite/20_util/duration/io.cc: New test.
diff --git a/libstdc++-v3/include/std/chrono b/libstdc++-v3/include/std/chrono
index c8060d7a67e..0662e26348f 100644
--- a/libstdc++-v3/include/std/chrono
+++ b/libstdc++-v3/include/std/chrono
@@ -37,6 +37,10 @@
#else
#include <bits/chrono.h>
+#if __cplusplus > 201703L
+# include <sstream> // ostringstream
+# include <bits/charconv.h>
+#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
@@ -2077,6 +2081,101 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
/// @}
} // inline namespace chrono_literals
} // inline namespace literals
+
+ namespace chrono
+ {
+ /// @addtogroup chrono
+ /// @{
+
+ /// @cond undocumented
+ namespace __detail
+ {
+ template<typename _Period>
+ const char*
+ __units_suffix_misc(char* __buf, size_t __n) noexcept
+ {
+ namespace __tc = std::__detail;
+ char* __p = __buf;
+ __p[0] = '[';
+ unsigned __nlen = __tc::__to_chars_len((uintmax_t)_Period::num);
+ __tc::__to_chars_10_impl(__p + 1, __nlen, (uintmax_t)_Period::num);
+ __p += 1 + __nlen;
+ if constexpr (_Period::den != 1)
+ {
+ __p[0] = '/';
+ unsigned __dlen = __tc::__to_chars_len((uintmax_t)_Period::den);
+ __tc::__to_chars_10_impl(__p + 1, __dlen,
(uintmax_t)_Period::den);
+ __p += 1 + __dlen;
+ }
+ __p[0] = ']';
+ __p[1] = 's';
+ __p[2] = '\0';
+ return __buf;
+ }
+
+ template<typename _Period, typename _CharT>
+ auto
+ __units_suffix(char* __buf, size_t __n) noexcept
+ {
+#define _GLIBCXX_UNITS_SUFFIX(period, suffix) \
+ if constexpr (is_same_v<_Period, period>) \
+ { \
+ if constexpr (is_same_v<_CharT, wchar_t>) \
+ return L##suffix; \
+ else \
+ return suffix; \
+ } \
+ else
+
+ _GLIBCXX_UNITS_SUFFIX(atto, "as")
+ _GLIBCXX_UNITS_SUFFIX(femto, "fs")
+ _GLIBCXX_UNITS_SUFFIX(pico, "ps")
+ _GLIBCXX_UNITS_SUFFIX(nano, "ns")
+ _GLIBCXX_UNITS_SUFFIX(micro, "\u00b5s")
+ _GLIBCXX_UNITS_SUFFIX(milli, "ms")
+ _GLIBCXX_UNITS_SUFFIX(centi, "cs")
+ _GLIBCXX_UNITS_SUFFIX(deci, "ds")
+ _GLIBCXX_UNITS_SUFFIX(ratio<1>, "s")
+ _GLIBCXX_UNITS_SUFFIX(deca, "das")
+ _GLIBCXX_UNITS_SUFFIX(hecto, "hs")
+ _GLIBCXX_UNITS_SUFFIX(kilo, "ks")
+ _GLIBCXX_UNITS_SUFFIX(mega, "Ms")
+ _GLIBCXX_UNITS_SUFFIX(giga, "Gs")
+ _GLIBCXX_UNITS_SUFFIX(tera, "Ts")
+ _GLIBCXX_UNITS_SUFFIX(tera, "Ts")
+ _GLIBCXX_UNITS_SUFFIX(peta, "Ps")
+ _GLIBCXX_UNITS_SUFFIX(exa, "Es")
+ _GLIBCXX_UNITS_SUFFIX(ratio<60>, "min")
+ _GLIBCXX_UNITS_SUFFIX(ratio<3600>, "h")
+ _GLIBCXX_UNITS_SUFFIX(ratio<86400>, "d")
+#undef _GLIBCXX_UNITS_SUFFIX
+ return __detail::__units_suffix_misc<_Period>(__buf, __n);
+ }
+ } // namespace __detail
+ /// @endcond
+
+ template<typename _CharT, typename _Traits,
+ typename _Rep, typename _Period>
+ inline basic_ostream<_CharT, _Traits>&
+ operator<<(std::basic_ostream<_CharT, _Traits>& __os,
+ const duration<_Rep, _Period>& __d)
+ {
+ using period = typename _Period::type;
+ char __buf[sizeof("[/]s") + 2 * numeric_limits<intmax_t>::digits10];
+ std::basic_ostringstream<_CharT, _Traits> __s;
+ __s.flags(__os.flags());
+ __s.imbue(__os.getloc());
+ __s.precision(__os.precision());
+ __s << __d.count();
+ __s << __detail::__units_suffix<period, _CharT>(__buf, sizeof(__buf));
+ __os << std::move(__s).str();
+ return __os;
+ }
+
+ // TODO: from_stream for duration
+
+ /// @} group chrono
+ } // namespace chrono
#endif // C++20
_GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/testsuite/20_util/duration/io.cc
b/libstdc++-v3/testsuite/20_util/duration/io.cc
new file mode 100644
index 00000000000..405e1afa440
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/duration/io.cc
@@ -0,0 +1,54 @@
+// { dg-options "-std=gnu++20" }
+// { dg-do run { target c++20 } }
+
+#include <chrono>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ using namespace std::chrono;
+ std::stringstream ss;
+ ss << 0s << '\n';
+ ss << 3h + 5min << '\n';
+ ss << duration<long, std::ratio<2>>(3) << '\n';
+ ss << duration<long, std::ratio<2, 3>>(9) << '\n';
+ std::string s;
+ std::getline(ss, s);
+ VERIFY( s == "0s" );
+ std::getline(ss, s);
+ VERIFY( s == "185min" );
+ std::getline(ss, s);
+ VERIFY( s == "3[2]s" );
+ std::getline(ss, s);
+ VERIFY( s == "9[2/3]s" );
+}
+
+void
+test02()
+{
+#ifdef _GLIBCXX_USE_WCHAR_T
+ using namespace std::chrono;
+ std::wstringstream ss;
+ ss << 0s << L'\n';
+ ss << 3h + 5min << L'\n';
+ ss << duration<long, std::ratio<2>>(3) << L'\n';
+ ss << duration<long, std::ratio<2, 3>>(9) << L'\n';
+ std::wstring s;
+ std::getline(ss, s);
+ VERIFY( s == L"0s" );
+ std::getline(ss, s);
+ VERIFY( s == L"185min" );
+ std::getline(ss, s);
+ VERIFY( s == L"3[2]s" );
+ std::getline(ss, s);
+ VERIFY( s == L"9[2/3]s" );
+#endif
+}
+
+int main()
+{
+ test01();
+ test02();
+}
