removed the use of str() in when building the log to improve perf even more

include/c11log/sinks/async_sink.h

@@ -67,7 +67,7 @@ inline c11log::sinks::async_sink::~async_sink()
 
 inline void c11log::sinks::async_sink::_sink_it(const details::log_msg& msg)
 {
-    if(!_active || msg.formatted.empty())
+    if(!_active)
         return;
     _q.push(msg);
 }

include/c11log/sinks/file_sinks.h

@@ -32,7 +32,7 @@ public:
 protected:
     void _sink_it(const details::log_msg& msg) override
     {
-        _flush_helper.write(msg.formatted, _ofstream);
+        _flush_helper.write(msg, _ofstream);
     }
 private:
     std::ofstream _ofstream;
@@ -71,7 +71,7 @@ protected:
             _rotate();
             _current_size = msg.formatted.size();
         }
-        _flush_helper.write(msg.formatted, _ofstream);
+        _flush_helper.write(msg, _ofstream);
     }
 
 
@@ -146,7 +146,7 @@ protected:
             _ofstream.open(_calc_filename(_base_filename, _extension));
             _midnight_tp = _calc_midnight_tp();
         }
-        _flush_helper.write(msg.formatted, _ofstream);
+        _flush_helper.write(msg, _ofstream);
     }
 
 private:

include/c11log/sinks/ostream_sink.h

@@ -24,7 +24,8 @@ public:
 protected:
     virtual void _sink_it(const details::log_msg& msg) override
     {
-        _ostream << msg.formatted;
+        auto buf = msg.formatted.buf();
+        _ostream.write(buf.data(), buf.size());
     }
     std::ostream& _ostream;
 };