Boost.Chrono: Moved to trunk

[SVN r67698]

example/explore_limits.cpp

@@ -0,0 +1,60 @@
+//  explore_limits.cpp  ----------------------------------------------------------//
+
+//  Copyright 2008 Howard Hinnant
+//  Copyright 2008 Beman Dawes
+//  Copyright 2009 Vicente J. Botet Escriba
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+/*
+This code was extracted by Vicente J. Botet Escriba from Beman Dawes time2_demo.cpp which
+was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
+Many thanks to Howard for making his code available under the Boost license.
+The original code was modified to conform to Boost conventions and to section
+20.9 Time utilities [time] of the C++ committee's working paper N2798.
+See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
+
+time2_demo contained this comment:
+
+    Much thanks to Andrei Alexandrescu,
+                   Walter Brown,
+                   Peter Dimov,
+                   Jeff Garland,
+                   Terry Golubiewski,
+                   Daniel Krugler,
+                   Anthony Williams.
+*/
+
+#include <boost/chrono/chrono.hpp>
+#include <boost/type_traits.hpp>
+
+#include <iostream>
+
+using namespace boost::chrono;
+
+
+void explore_limits()
+{
+    typedef duration<long long, boost::ratio_multiply<boost::ratio<24*3652425,10000>,
+      hours::period>::type> Years;
+#ifdef BOOST_CHRONO_HAS_CLOCK_MONOTONIC
+    monotonic_clock::time_point t1( Years(250));
+    monotonic_clock::time_point t2(-Years(250));
+#else
+    system_clock::time_point t1( Years(250));
+    system_clock::time_point t2(-Years(250));
+#endif
+    // nanosecond resolution is likely to overflow.  "up cast" to microseconds.
+    //   The "up cast" trades precision for range.
+    microseconds d = time_point_cast<microseconds>(t1) - time_point_cast<microseconds>(t2);
+    std::cout << d.count() << " microseconds\n";
+}
+
+
+int main()
+{
+    explore_limits();
+    return 0;
+}
+