#826 Build fix for ambiguity with >= libc++ 17

include/date/date.h

@@ -4228,7 +4228,7 @@ inline
 std::basic_ostream<CharT, Traits>&
 operator<<(std::basic_ostream<CharT, Traits>& os, const local_time<Duration>& ut)
 {
-    return (os << sys_time<Duration>{ut.time_since_epoch()});
+    return (date::operator<<(os, sys_time<Duration>{ut.time_since_epoch()}));
 }
 
 namespace detail

include/date/ptz.h

@@ -667,7 +667,7 @@ time_zone::name() const
     auto print_offset = [](seconds off)
         {
             std::string nm;
-            hh_mm_ss<seconds> offset{-off};
+            date::hh_mm_ss<seconds> offset{-off};
             if (offset.is_negative())
                 nm += '-';
             nm += std::to_string(offset.hours().count());

include/date/tz.h

@@ -231,8 +231,8 @@ nonexistent_local_time::make_msg(local_time<Duration> tp, const local_info& i)
        << i.first.abbrev << " and\n"
        << local_seconds{i.second.begin.time_since_epoch()} + i.second.offset << ' '
        << i.second.abbrev
-       << " which are both equivalent to\n"
-       << i.first.end << " UTC";
+       << " which are both equivalent to\n";
+    date::operator<<(os, i.first.end) << " UTC";
     return os.str();
 }
 

include/date/tz_private.h

@@ -289,8 +289,7 @@ struct transition
     std::ostream&
     operator<<(std::ostream& os, const transition& t)
     {
-        using date::operator<<;
-        os << t.timepoint << "Z ";
+        date::operator<<(os, t.timepoint) << "Z ";
         if (t.info->offset >= std::chrono::seconds{0})
             os << '+';
         os << make_time(t.info->offset);

src/tz.cpp

@@ -2729,8 +2729,7 @@ operator<<(std::ostream& os, const time_zone& z)
 std::ostream&
 operator<<(std::ostream& os, const leap_second& x)
 {
-    using namespace date;
-    return os << x.date_ << "  +";
+    return date::operator<<(os, x.date_) << "  +";
 }
 
 #if USE_OS_TZDB

test/clock_cast_test/local_t.pass.cpp

@@ -28,6 +28,7 @@ main()
 {
    using namespace date;
    using namespace std::chrono;
+   using date::local_days, date::local_t, date::January, date::July, date::Sunday;
 
    // self
    {

test/clock_cast_test/noncastable.pass.cpp

@@ -191,6 +191,7 @@ main()
     using namespace date;
     using namespace std::chrono;
     using sys_clock = std::chrono::system_clock;
+    using local_t = date::local_t;
 
     //steady_clock (must be different that sys_clock)
     static_assert(is_clock_castable<steady_clock, steady_clock>::value, "steady_clock -> steady_clock");

test/date_test/durations_output.pass.cpp

@@ -36,135 +36,135 @@ void test_SI()
    // atto
    {
      duration<int, std::atto> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13as");
      os.str("");
    }
 
    // femto
    {
      duration<int, std::femto> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13fs");
      os.str("");
    }
 
    // pico
    {
      duration<int, std::pico> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13ps");
      os.str("");
    }
 
    // nano
    {
      duration<int, std::nano> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13ns");
      os.str("");
    }
 
    // mikro
    {
      duration<int, std::micro> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13\xC2\xB5s");
      os.str("");
    }
 
    // milli
    {
      duration<int, std::milli> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13ms");
      os.str("");
    }
 
    // centi
    {
      duration<int, std::centi> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13cs");
      os.str("");
    }
 
    // deci
    {
      duration<int, std::deci> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13ds");
      os.str("");
    }
 
    // seconds
    {
      duration<int> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13s");
      os.str("");
    }
 
    // deca
    {
      duration<int, std::deca> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13das");
      os.str("");
    }
 
    // hecto
    {
      duration<int, std::hecto> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13hs");
      os.str("");
    }
 
    // kilo
    {
      duration<int, std::kilo> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13ks");
      os.str("");
    }
 
    // mega
    {
      duration<int, std::mega> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13Ms");
      os.str("");
    }
 
    // giga
    {
      duration<int, std::giga> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13Gs");
      os.str("");
    }
 
    // tera
    {
      duration<int, std::tera> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13Ts");
      os.str("");
    }
 
    // peta
    {
      duration<int, std::peta> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13Ps");
      os.str("");
    }
 
    // femto
    {
      duration<int, std::exa> d(13);
-     os << d;
+     date::operator<<(os, d);
      assert(os.str() == "13Es");
      os.str("");
    }
@@ -180,23 +180,23 @@ void test_calendar()
    // minutes
    {
       minutes d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13min");
       os.str("");
    }
 
    // hours
    {
       hours d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13h");
       os.str("");
    }
 
    // days
    {
       days d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13d");
       os.str("");
    }
@@ -212,39 +212,39 @@ void test_integral_scale()
    // ratio 123 / 1
    {
       duration<int, std::ratio<123, 1>> d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[123]s");
       os.str("");
    }
 
    // ratio 100 / 4 = ratio 25 / 1
    {
       duration<int, std::ratio<25, 1>> d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[25]s");
       os.str("");
    }
 
    // weeks = ratio 7 * 24 * 60 * 60 / 1 = ratio 604800 / 1
    {
       weeks d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[604800]s");
       os.str("");
    }
 
    // years = 146097/400 days = ratio 146097/400 * 24 * 60 * 60 = ratio 31556952 / 1
    {
       years d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[31556952]s");
       os.str("");
    }
 
    // months = 1/12 years = ratio 1/12 * 31556952  = ratio 2629746 / 1
    {
       months d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[2629746]s");
       os.str("");
    }
@@ -260,23 +260,23 @@ void test_ratio_scale()
    // ratio 1 / 2
    {
       duration<int, std::ratio<1, 2>> d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[1/2]s");
       os.str("");
    }
 
    // ratio 100 / 3
    {
       duration<int, std::ratio<100, 3>> d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[100/3]s");
       os.str("");
    }
 
    // ratio 100 / 6 = ratio 50 / 3
    {
       duration<int, std::ratio<100, 6>> d(13);
-      os << d;
+      date::operator<<(os, d);
       assert(os.str() == "13[50/3]s");
       os.str("");
    }