More const int definitions for VC++

base/time/time_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 // Windows Timer Primer
 //
 // A good article:  http://www.ddj.com/windows/184416651
 // A good mozilla bug:  http://bugzilla.mozilla.org/show_bug.cgi?id=363258
 //
@@ skipping 113 matching lines @@
 
 // Time -----------------------------------------------------------------------
 
 // The internal representation of Time uses FILETIME, whose epoch is 1601-01-01
 // 00:00:00 UTC.  ((1970-1601)*365+89)*24*60*60*1000*1000, where 89 is the
 // number of leap year days between 1601 and 1970: (1970-1601)/4 excluding
 // 1700, 1800, and 1900.
 // static
 const int64 Time::kTimeTToMicrosecondsOffset = INT64_C(11644473600000000);
 
+// VS 2015 and above allow these definitions and in this case require them

[danakj, 2015/10/30 20:23:30]

nit: period

[brucedawson, 2015/10/30 20:36:59]

Done.

+#if _MSC_VER >= 1900
+const int64 base::Time::kQPCOverflowThreshold;

[danakj, 2015/10/30 20:23:30]

Other statics that have storage seem to be initialized at the storage site
instead of in the header. Is there a reason to not unconditionally define this
storage and initialize it here also?

This came up in the static vs enum class discussion on chromium-dev and I
thought the outcome there was to always define storage for statics:
https://groups.google.com/a/chromium.org/d/msg/chromium-dev/hDqJ4KBVqog/cQu6D...

+#endif
+
 // static
 Time Time::Now() {
   if (initial_time == 0)
     InitializeClock();
 
   // We implement time using the high-resolution timers so that we can get
   // timeouts which are smaller than 10-15ms.  If we just used
   // CurrentWallclockMicroseconds(), we'd have the less-granular timer.
   //
   // To make this work, we initialize the clock (initial_time) and the
@@ skipping 477 matching lines @@
 TimeTicks TimeTicks::FromQPCValue(LONGLONG qpc_value) {
   return TimeTicks() + QPCValueToTimeDelta(qpc_value);
 }
 
 // TimeDelta ------------------------------------------------------------------
 
 // static
 TimeDelta TimeDelta::FromQPCValue(LONGLONG qpc_value) {
   return QPCValueToTimeDelta(qpc_value);
 }