[trivial] restrict timer format changes to Logging. (#199)

src/search/utils/logging.cc

@@ -133,4 +133,16 @@ static plugins::TypedEnumPlugin<Verbosity> _enum_plugin({
         {"verbose", "full output"},
         {"debug", "like verbose with additional debug output"}
     });
+
+void Log::add_prefix() const {
+    stream << "[t=";
+    streamsize previous_precision = cout.precision(TIMER_PRECISION);
+    ios_base::fmtflags previous_flags = stream.flags();
+    stream.setf(ios_base::fixed, ios_base::floatfield);
+    stream << g_timer;
+    stream.flags(previous_flags);
+    cout.precision(previous_precision);
+    stream << ", "
+           << get_peak_memory_in_kb() << " KB] ";
+}
 }

src/search/utils/logging.h

@@ -32,9 +32,11 @@ enum class Verbosity {
   Internal class encapsulated by LogProxy.
 */
 class Log {
+    static const int TIMER_PRECISION = 6;
     std::ostream &stream;
     const Verbosity verbosity;
     bool line_has_started;
+    void add_prefix() const;
 
 public:
     explicit Log(Verbosity verbosity)
@@ -45,10 +47,8 @@ class Log {
     Log &operator<<(const T &elem) {
         if (!line_has_started) {
             line_has_started = true;
-            stream << "[t=" << g_timer << ", "
-                   << get_peak_memory_in_kb() << " KB] ";
+            add_prefix();
         }
-
         stream << elem;
         return *this;
     }