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diff --git a/src/boost/libs/chrono/example/time2_demo.cpp b/src/boost/libs/chrono/example/time2_demo.cpp
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+// time2_demo.cpp ----------------------------------------------------------//
+
+// Copyright 2008 Howard Hinnant
+// Copyright 2008 Beman Dawes
+
+// Distributed under the Boost Software License, Version 1.0.
+// See http://www.boost.org/LICENSE_1_0.txt
+
+/*
+
+This code 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.
+*/
+
+#define _CRT_SECURE_NO_WARNINGS // disable VC++ foolishness
+
+#include <boost/chrono/chrono.hpp>
+#include <boost/type_traits.hpp>
+
+#include <cassert>
+#include <climits>
+#include <iostream>
+#include <ostream>
+#include <stdexcept>
+
+#include <windows.h>
+
+namespace
+{
+ //struct timeval {
+ // long tv_sec; /* seconds */
+ // long tv_usec; /* and microseconds */
+ //};
+
+ int gettimeofday(struct timeval * tp, void *)
+ {
+ FILETIME ft;
+ ::GetSystemTimeAsFileTime( &ft ); // never fails
+ long long t = (static_cast<long long>(ft.dwHighDateTime) << 32) | ft.dwLowDateTime;
+ # if !defined( BOOST_MSVC ) || BOOST_MSVC > 1300 // > VC++ 7.0
+ t -= 116444736000000000LL;
+ # else
+ t -= 116444736000000000;
+ # endif
+ t /= 10; // microseconds
+ tp->tv_sec = static_cast<long>( t / 1000000UL);
+ tp->tv_usec = static_cast<long>( t % 1000000UL);
+ return 0;
+ }
+} // unnamed namespace
+
+//////////////////////////////////////////////////////////
+///////////// simulated thread interface /////////////////
+//////////////////////////////////////////////////////////
+
+
+namespace std {
+
+void __print_time(boost::chrono::system_clock::time_point t)
+{
+ using namespace boost::chrono;
+ time_t c_time = system_clock::to_time_t(t);
+ std::tm* tmptr = std::localtime(&c_time);
+ system_clock::duration d = t.time_since_epoch();
+ std::cout << tmptr->tm_hour << ':' << tmptr->tm_min << ':' << tmptr->tm_sec
+ << '.' << (d - duration_cast<seconds>(d)).count();
+}
+
+namespace this_thread {
+
+template <class Rep, class Period>
+void sleep_for(const boost::chrono::duration<Rep, Period>& d)
+{
+ boost::chrono::microseconds t = boost::chrono::duration_cast<boost::chrono::microseconds>(d);
+ if (t < d)
+ ++t;
+ if (t > boost::chrono::microseconds(0))
+ std::cout << "sleep_for " << t.count() << " microseconds\n";
+}
+
+template <class Clock, class Duration>
+void sleep_until(const boost::chrono::time_point<Clock, Duration>& t)
+{
+ using namespace boost::chrono;
+ typedef time_point<Clock, Duration> Time;
+ typedef system_clock::time_point SysTime;
+ if (t > Clock::now())
+ {
+ typedef typename boost::common_type<typename Time::duration,
+ typename SysTime::duration>::type D;
+ /* auto */ D d = t - Clock::now();
+ microseconds us = duration_cast<microseconds>(d);
+ if (us < d)
+ ++us;
+ SysTime st = system_clock::now() + us;
+ std::cout << "sleep_until ";
+ __print_time(st);
+ std::cout << " which is " << (st - system_clock::now()).count() << " microseconds away\n";
+ }
+}
+
+} // this_thread
+
+struct mutex {};
+
+struct timed_mutex
+{
+ bool try_lock() {std::cout << "timed_mutex::try_lock()\n"; return true;}
+
+ template <class Rep, class Period>
+ bool try_lock_for(const boost::chrono::duration<Rep, Period>& d)
+ {
+ boost::chrono::microseconds t = boost::chrono::duration_cast<boost::chrono::microseconds>(d);
+ if (t <= boost::chrono::microseconds(0))
+ return try_lock();
+ std::cout << "try_lock_for " << t.count() << " microseconds\n";
+ return true;
+ }
+
+ template <class Clock, class Duration>
+ bool try_lock_until(const boost::chrono::time_point<Clock, Duration>& t)
+ {
+ using namespace boost::chrono;
+ typedef time_point<Clock, Duration> Time;
+ typedef system_clock::time_point SysTime;
+ if (t <= Clock::now())
+ return try_lock();
+ typedef typename boost::common_type<typename Time::duration,
+ typename Clock::duration>::type D;
+ /* auto */ D d = t - Clock::now();
+ microseconds us = duration_cast<microseconds>(d);
+ SysTime st = system_clock::now() + us;
+ std::cout << "try_lock_until ";
+ __print_time(st);
+ std::cout << " which is " << (st - system_clock::now()).count()
+ << " microseconds away\n";
+ return true;
+ }
+};
+
+struct condition_variable
+{
+ template <class Rep, class Period>
+ bool wait_for(mutex&, const boost::chrono::duration<Rep, Period>& d)
+ {
+ boost::chrono::microseconds t = boost::chrono::duration_cast<boost::chrono::microseconds>(d);
+ std::cout << "wait_for " << t.count() << " microseconds\n";
+ return true;
+ }
+
+ template <class Clock, class Duration>
+ bool wait_until(mutex&, const boost::chrono::time_point<Clock, Duration>& t)
+ {
+ using namespace boost::chrono;
+ typedef time_point<Clock, Duration> Time;
+ typedef system_clock::time_point SysTime;
+ if (t <= Clock::now())
+ return false;
+ typedef typename boost::common_type<typename Time::duration,
+ typename Clock::duration>::type D;
+ /* auto */ D d = t - Clock::now();
+ microseconds us = duration_cast<microseconds>(d);
+ SysTime st = system_clock::now() + us;
+ std::cout << "wait_until ";
+ __print_time(st);
+ std::cout << " which is " << (st - system_clock::now()).count()
+ << " microseconds away\n";
+ return true;
+ }
+};
+
+} // namespace std
+
+//////////////////////////////////////////////////////////
+//////////// Simple sleep and wait examples //////////////
+//////////////////////////////////////////////////////////
+
+std::mutex m;
+std::timed_mutex mut;
+std::condition_variable cv;
+
+void basic_examples()
+{
+ std::cout << "Running basic examples\n";
+ using namespace std;
+ using namespace boost::chrono;
+ system_clock::time_point time_limit = system_clock::now() + seconds(4) + milliseconds(500);
+ this_thread::sleep_for(seconds(3));
+ this_thread::sleep_for(nanoseconds(300));
+ this_thread::sleep_until(time_limit);
+// this_thread::sleep_for(time_limit); // desired compile-time error
+// this_thread::sleep_until(seconds(3)); // desired compile-time error
+ mut.try_lock_for(milliseconds(30));
+ mut.try_lock_until(time_limit);
+// mut.try_lock_for(time_limit); // desired compile-time error
+// mut.try_lock_until(milliseconds(30)); // desired compile-time error
+ cv.wait_for(m, minutes(1)); // real code would put this in a loop
+ cv.wait_until(m, time_limit); // real code would put this in a loop
+ // For those who prefer floating point
+ this_thread::sleep_for(duration<double>(0.25));
+ this_thread::sleep_until(system_clock::now() + duration<double>(1.5));
+}
+
+//////////////////////////////////////////////////////////
+//////////////////// User1 Example ///////////////////////
+//////////////////////////////////////////////////////////
+
+namespace User1
+{
+// Example type-safe "physics" code interoperating with boost::chrono::duration types
+// and taking advantage of the boost::ratio infrastructure and design philosophy.
+
+// length - mimics boost::chrono::duration except restricts representation to double.
+// Uses boost::ratio facilities for length units conversions.
+
+template <class Ratio>
+class length
+{
+public:
+ typedef Ratio ratio;
+private:
+ double len_;
+public:
+
+ length() : len_(1) {}
+ length(const double& len) : len_(len) {}
+
+ // conversions
+ template <class R>
+ length(const length<R>& d)
+ : len_(d.count() * boost::ratio_divide<Ratio, R>::type::den /
+ boost::ratio_divide<Ratio, R>::type::num) {}
+
+ // observer
+
+ double count() const {return len_;}
+
+ // arithmetic
+
+ length& operator+=(const length& d) {len_ += d.count(); return *this;}
+ length& operator-=(const length& d) {len_ -= d.count(); return *this;}
+
+ length operator+() const {return *this;}
+ length operator-() const {return length(-len_);}
+
+ length& operator*=(double rhs) {len_ *= rhs; return *this;}
+ length& operator/=(double rhs) {len_ /= rhs; return *this;}
+};
+
+// Sparse sampling of length units
+typedef length<boost::ratio<1> > meter; // set meter as "unity"
+typedef length<boost::centi> centimeter; // 1/100 meter
+typedef length<boost::kilo> kilometer; // 1000 meters
+typedef length<boost::ratio<254, 10000> > inch; // 254/10000 meters
+// length takes ratio instead of two integral types so that definitions can be made like so:
+typedef length<boost::ratio_multiply<boost::ratio<12>, inch::ratio>::type> foot; // 12 inchs
+typedef length<boost::ratio_multiply<boost::ratio<5280>, foot::ratio>::type> mile; // 5280 feet
+
+// Need a floating point definition of seconds
+typedef boost::chrono::duration<double> seconds; // unity
+// Demo of (scientific) support for sub-nanosecond resolutions
+typedef boost::chrono::duration<double, boost::pico> picosecond; // 10^-12 seconds
+typedef boost::chrono::duration<double, boost::femto> femtosecond; // 10^-15 seconds
+typedef boost::chrono::duration<double, boost::atto> attosecond; // 10^-18 seconds
+
+// A very brief proof-of-concept for SIUnits-like library
+// Hard-wired to floating point seconds and meters, but accepts other units (shown in testUser1())
+template <class R1, class R2>
+class quantity
+{
+ double q_;
+public:
+ quantity() : q_(1) {}
+
+ double get() const {return q_;}
+ void set(double q) {q_ = q;}
+};
+
+template <>
+class quantity<boost::ratio<1>, boost::ratio<0> >
+{
+ double q_;
+public:
+ quantity() : q_(1) {}
+ quantity(seconds d) : q_(d.count()) {} // note: only User1::seconds needed here
+
+ double get() const {return q_;}
+ void set(double q) {q_ = q;}
+};
+
+template <>
+class quantity<boost::ratio<0>, boost::ratio<1> >
+{
+ double q_;
+public:
+ quantity() : q_(1) {}
+ quantity(meter d) : q_(d.count()) {} // note: only User1::meter needed here
+
+ double get() const {return q_;}
+ void set(double q) {q_ = q;}
+};
+
+template <>
+class quantity<boost::ratio<0>, boost::ratio<0> >
+{
+ double q_;
+public:
+ quantity() : q_(1) {}
+ quantity(double d) : q_(d) {}
+
+ double get() const {return q_;}
+ void set(double q) {q_ = q;}
+};
+
+// Example SI-Units
+typedef quantity<boost::ratio<0>, boost::ratio<0> > Scalar;
+typedef quantity<boost::ratio<1>, boost::ratio<0> > Time; // second
+typedef quantity<boost::ratio<0>, boost::ratio<1> > Distance; // meter
+typedef quantity<boost::ratio<-1>, boost::ratio<1> > Speed; // meter/second
+typedef quantity<boost::ratio<-2>, boost::ratio<1> > Acceleration; // meter/second^2
+
+template <class R1, class R2, class R3, class R4>
+quantity<typename boost::ratio_subtract<R1, R3>::type, typename boost::ratio_subtract<R2, R4>::type>
+operator/(const quantity<R1, R2>& x, const quantity<R3, R4>& y)
+{
+ typedef quantity<typename boost::ratio_subtract<R1, R3>::type, typename boost::ratio_subtract<R2, R4>::type> R;
+ R r;
+ r.set(x.get() / y.get());
+ return r;
+}
+
+template <class R1, class R2, class R3, class R4>
+quantity<typename boost::ratio_add<R1, R3>::type, typename boost::ratio_add<R2, R4>::type>
+operator*(const quantity<R1, R2>& x, const quantity<R3, R4>& y)
+{
+ typedef quantity<typename boost::ratio_add<R1, R3>::type, typename boost::ratio_add<R2, R4>::type> R;
+ R r;
+ r.set(x.get() * y.get());
+ return r;
+}
+
+template <class R1, class R2>
+quantity<R1, R2>
+operator+(const quantity<R1, R2>& x, const quantity<R1, R2>& y)
+{
+ typedef quantity<R1, R2> R;
+ R r;
+ r.set(x.get() + y.get());
+ return r;
+}
+
+template <class R1, class R2>
+quantity<R1, R2>
+operator-(const quantity<R1, R2>& x, const quantity<R1, R2>& y)
+{
+ typedef quantity<R1, R2> R;
+ R r;
+ r.set(x.get() - y.get());
+ return r;
+}
+
+// Example type-safe physics function
+Distance
+compute_distance(Speed v0, Time t, Acceleration a)
+{
+ return v0 * t + Scalar(.5) * a * t * t; // if a units mistake is made here it won't compile
+}
+
+} // User1
+
+
+// Exercise example type-safe physics function and show interoperation
+// of custom time durations (User1::seconds) and standard time durations (std::hours).
+// Though input can be arbitrary (but type-safe) units, output is always in SI-units
+// (a limitation of the simplified Units lib demoed here).
+void testUser1()
+{
+ std::cout << "*************\n";
+ std::cout << "* testUser1 *\n";
+ std::cout << "*************\n";
+ User1::Distance d( User1::mile(110) );
+ User1::Time t( boost::chrono::hours(2) );
+ User1::Speed s = d / t;
+ std::cout << "Speed = " << s.get() << " meters/sec\n";
+ User1::Acceleration a = User1::Distance( User1::foot(32.2) ) / User1::Time() / User1::Time();
+ std::cout << "Acceleration = " << a.get() << " meters/sec^2\n";
+ User1::Distance df = compute_distance(s, User1::Time( User1::seconds(0.5) ), a);
+ std::cout << "Distance = " << df.get() << " meters\n";
+ std::cout << "There are " << User1::mile::ratio::den << '/' << User1::mile::ratio::num << " miles/meter";
+ User1::meter mt = 1;
+ User1::mile mi = mt;
+ std::cout << " which is approximately " << mi.count() << '\n';
+ std::cout << "There are " << User1::mile::ratio::num << '/' << User1::mile::ratio::den << " meters/mile";
+ mi = 1;
+ mt = mi;
+ std::cout << " which is approximately " << mt.count() << '\n';
+ User1::attosecond as(1);
+ User1::seconds sec = as;
+ std::cout << "1 attosecond is " << sec.count() << " seconds\n";
+ std::cout << "sec = as; // compiles\n";
+ sec = User1::seconds(1);
+ as = sec;
+ std::cout << "1 second is " << as.count() << " attoseconds\n";
+ std::cout << "as = sec; // compiles\n";
+ std::cout << "\n";
+}
+
+//////////////////////////////////////////////////////////
+//////////////////// User2 Example ///////////////////////
+//////////////////////////////////////////////////////////
+
+// Demonstrate User2:
+// A "saturating" signed integral type is developed. This type has +/- infinity and a nan
+// (like IEEE floating point) but otherwise obeys signed integral arithmetic.
+// This class is subsequently used as the rep in boost::chrono::duration to demonstrate a
+// duration class that does not silently ignore overflow.
+
+namespace User2
+{
+
+template <class I>
+class saturate
+{
+public:
+ typedef I int_type;
+
+ static const int_type nan = int_type(int_type(1) << (sizeof(int_type) * CHAR_BIT - 1));
+ static const int_type neg_inf = nan + 1;
+ static const int_type pos_inf = -neg_inf;
+private:
+ int_type i_;
+
+// static_assert(std::is_integral<int_type>::value && std::is_signed<int_type>::value,
+// "saturate only accepts signed integral types");
+// static_assert(nan == -nan && neg_inf < pos_inf,
+// "saturate assumes two's complement hardware for signed integrals");
+
+public:
+ saturate() : i_(nan) {}
+ explicit saturate(int_type i) : i_(i) {}
+ // explicit
+ operator int_type() const;
+
+ saturate& operator+=(saturate x);
+ saturate& operator-=(saturate x) {return *this += -x;}
+ saturate& operator*=(saturate x);
+ saturate& operator/=(saturate x);
+ saturate& operator%=(saturate x);
+
+ saturate operator- () const {return saturate(-i_);}
+ saturate& operator++() {*this += saturate(int_type(1)); return *this;}
+ saturate operator++(int) {saturate tmp(*this); ++(*this); return tmp;}
+ saturate& operator--() {*this -= saturate(int_type(1)); return *this;}
+ saturate operator--(int) {saturate tmp(*this); --(*this); return tmp;}
+
+ friend saturate operator+(saturate x, saturate y) {return x += y;}
+ friend saturate operator-(saturate x, saturate y) {return x -= y;}
+ friend saturate operator*(saturate x, saturate y) {return x *= y;}
+ friend saturate operator/(saturate x, saturate y) {return x /= y;}
+ friend saturate operator%(saturate x, saturate y) {return x %= y;}
+
+ friend bool operator==(saturate x, saturate y)
+ {
+ if (x.i_ == nan || y.i_ == nan)
+ return false;
+ return x.i_ == y.i_;
+ }
+
+ friend bool operator!=(saturate x, saturate y) {return !(x == y);}
+
+ friend bool operator<(saturate x, saturate y)
+ {
+ if (x.i_ == nan || y.i_ == nan)
+ return false;
+ return x.i_ < y.i_;
+ }
+
+ friend bool operator<=(saturate x, saturate y)
+ {
+ if (x.i_ == nan || y.i_ == nan)
+ return false;
+ return x.i_ <= y.i_;
+ }
+
+ friend bool operator>(saturate x, saturate y)
+ {
+ if (x.i_ == nan || y.i_ == nan)
+ return false;
+ return x.i_ > y.i_;
+ }
+
+ friend bool operator>=(saturate x, saturate y)
+ {
+ if (x.i_ == nan || y.i_ == nan)
+ return false;
+ return x.i_ >= y.i_;
+ }
+
+ friend std::ostream& operator<<(std::ostream& os, saturate s)
+ {
+ switch (s.i_)
+ {
+ case pos_inf:
+ return os << "inf";
+ case nan:
+ return os << "nan";
+ case neg_inf:
+ return os << "-inf";
+ };
+ return os << s.i_;
+ }
+};
+
+template <class I>
+saturate<I>::operator int_type() const
+{
+ switch (i_)
+ {
+ case nan:
+ case neg_inf:
+ case pos_inf:
+ throw std::out_of_range("saturate special value can not convert to int_type");
+ }
+ return i_;
+}
+
+template <class I>
+saturate<I>&
+saturate<I>::operator+=(saturate x)
+{
+ switch (i_)
+ {
+ case pos_inf:
+ switch (x.i_)
+ {
+ case neg_inf:
+ case nan:
+ i_ = nan;
+ }
+ return *this;
+ case nan:
+ return *this;
+ case neg_inf:
+ switch (x.i_)
+ {
+ case pos_inf:
+ case nan:
+ i_ = nan;
+ }
+ return *this;
+ }
+ switch (x.i_)
+ {
+ case pos_inf:
+ case neg_inf:
+ case nan:
+ i_ = x.i_;
+ return *this;
+ }
+ if (x.i_ >= 0)
+ {
+ if (i_ < pos_inf - x.i_)
+ i_ += x.i_;
+ else
+ i_ = pos_inf;
+ return *this;
+ }
+ if (i_ > neg_inf - x.i_)
+ i_ += x.i_;
+ else
+ i_ = neg_inf;
+ return *this;
+}
+
+template <class I>
+saturate<I>&
+saturate<I>::operator*=(saturate x)
+{
+ switch (i_)
+ {
+ case 0:
+ switch (x.i_)
+ {
+ case pos_inf:
+ case neg_inf:
+ case nan:
+ i_ = nan;
+ }
+ return *this;
+ case pos_inf:
+ switch (x.i_)
+ {
+ case nan:
+ case 0:
+ i_ = nan;
+ return *this;
+ }
+ if (x.i_ < 0)
+ i_ = neg_inf;
+ return *this;
+ case nan:
+ return *this;
+ case neg_inf:
+ switch (x.i_)
+ {
+ case nan:
+ case 0:
+ i_ = nan;
+ return *this;
+ }
+ if (x.i_ < 0)
+ i_ = pos_inf;
+ return *this;
+ }
+ switch (x.i_)
+ {
+ case 0:
+ i_ = 0;
+ return *this;
+ case nan:
+ i_ = nan;
+ return *this;
+ case pos_inf:
+ if (i_ < 0)
+ i_ = neg_inf;
+ else
+ i_ = pos_inf;
+ return *this;
+ case neg_inf:
+ if (i_ < 0)
+ i_ = pos_inf;
+ else
+ i_ = neg_inf;
+ return *this;
+ }
+ int s = (i_ < 0 ? -1 : 1) * (x.i_ < 0 ? -1 : 1);
+ i_ = i_ < 0 ? -i_ : i_;
+ int_type x_i_ = x.i_ < 0 ? -x.i_ : x.i_;
+ if (i_ <= pos_inf / x_i_)
+ i_ *= x_i_;
+ else
+ i_ = pos_inf;
+ i_ *= s;
+ return *this;
+}
+
+template <class I>
+saturate<I>&
+saturate<I>::operator/=(saturate x)
+{
+ switch (x.i_)
+ {
+ case pos_inf:
+ case neg_inf:
+ switch (i_)
+ {
+ case pos_inf:
+ case neg_inf:
+ case nan:
+ i_ = nan;
+ break;
+ default:
+ i_ = 0;
+ break;
+ }
+ return *this;
+ case nan:
+ i_ = nan;
+ return *this;
+ case 0:
+ switch (i_)
+ {
+ case pos_inf:
+ case neg_inf:
+ case nan:
+ return *this;
+ case 0:
+ i_ = nan;
+ return *this;
+ }
+ if (i_ > 0)
+ i_ = pos_inf;
+ else
+ i_ = neg_inf;
+ return *this;
+ }
+ switch (i_)
+ {
+ case 0:
+ case nan:
+ return *this;
+ case pos_inf:
+ case neg_inf:
+ if (x.i_ < 0)
+ i_ = -i_;
+ return *this;
+ }
+ i_ /= x.i_;
+ return *this;
+}
+
+template <class I>
+saturate<I>&
+saturate<I>::operator%=(saturate x)
+{
+// *this -= *this / x * x; // definition
+ switch (x.i_)
+ {
+ case nan:
+ case neg_inf:
+ case 0:
+ case pos_inf:
+ i_ = nan;
+ return *this;
+ }
+ switch (i_)
+ {
+ case neg_inf:
+ case pos_inf:
+ i_ = nan;
+ case nan:
+ return *this;
+ }
+ i_ %= x.i_;
+ return *this;
+}
+
+// Demo overflow-safe integral durations ranging from picoseconds resolution to millennium resolution
+typedef boost::chrono::duration<saturate<long long>, boost::pico > picoseconds;
+typedef boost::chrono::duration<saturate<long long>, boost::nano > nanoseconds;
+typedef boost::chrono::duration<saturate<long long>, boost::micro > microseconds;
+typedef boost::chrono::duration<saturate<long long>, boost::milli > milliseconds;
+typedef boost::chrono::duration<saturate<long long> > seconds;
+typedef boost::chrono::duration<saturate<long long>, boost::ratio< 60LL> > minutes;
+typedef boost::chrono::duration<saturate<long long>, boost::ratio< 3600LL> > hours;
+typedef boost::chrono::duration<saturate<long long>, boost::ratio< 86400LL> > days;
+typedef boost::chrono::duration<saturate<long long>, boost::ratio< 31556952LL> > years;
+typedef boost::chrono::duration<saturate<long long>, boost::ratio<31556952000LL> > millennium;
+
+} // User2
+
+// Demonstrate custom promotion rules (needed only if there are no implicit conversions)
+namespace User2 { namespace detail {
+
+template <class T1, class T2, bool = boost::is_integral<T1>::value>
+struct promote_helper;
+
+template <class T1, class T2>
+struct promote_helper<T1, saturate<T2>, true> // integral
+{
+ typedef typename boost::common_type<T1, T2>::type rep;
+ typedef User2::saturate<rep> type;
+};
+
+template <class T1, class T2>
+struct promote_helper<T1, saturate<T2>, false> // floating
+{
+ typedef T1 type;
+};
+
+} }
+
+namespace boost
+{
+
+template <class T1, class T2>
+struct common_type<User2::saturate<T1>, User2::saturate<T2> >
+{
+ typedef typename common_type<T1, T2>::type rep;
+ typedef User2::saturate<rep> type;
+};
+
+template <class T1, class T2>
+struct common_type<T1, User2::saturate<T2> >
+ : User2::detail::promote_helper<T1, User2::saturate<T2> > {};
+
+template <class T1, class T2>
+struct common_type<User2::saturate<T1>, T2>
+ : User2::detail::promote_helper<T2, User2::saturate<T1> > {};
+
+
+// Demonstrate specialization of duration_values:
+
+namespace chrono {
+
+template <class I>
+struct duration_values<User2::saturate<I> >
+{
+ typedef User2::saturate<I> Rep;
+public:
+ static Rep zero() {return Rep(0);}
+ static Rep max BOOST_PREVENT_MACRO_SUBSTITUTION () {return Rep(Rep::pos_inf-1);}
+ static Rep min BOOST_PREVENT_MACRO_SUBSTITUTION () {return -(max) ();}
+};
+
+} // namespace chrono
+
+} // namespace boost
+
+
+void testUser2()
+{
+ std::cout << "*************\n";
+ std::cout << "* testUser2 *\n";
+ std::cout << "*************\n";
+ using namespace User2;
+ typedef seconds::rep sat;
+ years yr(sat(100));
+ std::cout << "100 years expressed as years = " << yr.count() << '\n';
+ nanoseconds ns = yr;
+ std::cout << "100 years expressed as nanoseconds = " << ns.count() << '\n';
+ ns += yr;
+ std::cout << "200 years expressed as nanoseconds = " << ns.count() << '\n';
+ ns += yr;
+ std::cout << "300 years expressed as nanoseconds = " << ns.count() << '\n';
+// yr = ns; // does not compile
+ std::cout << "yr = ns; // does not compile\n";
+// picoseconds ps1 = yr; // does not compile, compile-time overflow in ratio arithmetic
+ std::cout << "ps = yr; // does not compile\n";
+ ns = yr;
+ picoseconds ps = ns;
+ std::cout << "100 years expressed as picoseconds = " << ps.count() << '\n';
+ ps = ns / sat(1000);
+ std::cout << "0.1 years expressed as picoseconds = " << ps.count() << '\n';
+ yr = years(sat(-200000000));
+ std::cout << "200 million years ago encoded in years: " << yr.count() << '\n';
+ days d = boost::chrono::duration_cast<days>(yr);
+ std::cout << "200 million years ago encoded in days: " << d.count() << '\n';
+ millennium c = boost::chrono::duration_cast<millennium>(yr);
+ std::cout << "200 million years ago encoded in millennium: " << c.count() << '\n';
+ std::cout << "Demonstrate \"uninitialized protection\" behavior:\n";
+ seconds sec;
+ for (++sec; sec < seconds(sat(10)); ++sec)
+ ;
+ std::cout << sec.count() << '\n';
+ std::cout << "\n";
+}
+
+void testStdUser()
+{
+ std::cout << "***************\n";
+ std::cout << "* testStdUser *\n";
+ std::cout << "***************\n";
+ using namespace boost::chrono;
+ hours hr = hours(100);
+ std::cout << "100 hours expressed as hours = " << hr.count() << '\n';
+ nanoseconds ns = hr;
+ std::cout << "100 hours expressed as nanoseconds = " << ns.count() << '\n';
+ ns += hr;
+ std::cout << "200 hours expressed as nanoseconds = " << ns.count() << '\n';
+ ns += hr;
+ std::cout << "300 hours expressed as nanoseconds = " << ns.count() << '\n';
+// hr = ns; // does not compile
+ std::cout << "hr = ns; // does not compile\n";
+// hr * ns; // does not compile
+ std::cout << "hr * ns; // does not compile\n";
+ duration<double> fs(2.5);
+ std::cout << "duration<double> has count() = " << fs.count() << '\n';
+// seconds sec = fs; // does not compile
+ std::cout << "seconds sec = duration<double> won't compile\n";
+ seconds sec = duration_cast<seconds>(fs);
+ std::cout << "seconds has count() = " << sec.count() << '\n';
+ std::cout << "\n";
+}
+
+// timeval clock demo
+// Demonstrate the use of a timeval-like struct to be used as the representation
+// type for both duraiton and time_point.
+
+namespace timeval_demo
+{
+
+class xtime {
+private:
+ long tv_sec;
+ long tv_usec;
+
+ void fixup() {
+ if (tv_usec < 0) {
+ tv_usec += 1000000;
+ --tv_sec;
+ }
+ }
+
+public:
+
+ explicit xtime(long sec, long usec) {
+ tv_sec = sec;
+ tv_usec = usec;
+ if (tv_usec < 0 || tv_usec >= 1000000) {
+ tv_sec += tv_usec / 1000000;
+ tv_usec %= 1000000;
+ fixup();
+ }
+ }
+
+ explicit xtime(long long usec)
+ {
+ tv_usec = static_cast<long>(usec % 1000000);
+ tv_sec = static_cast<long>(usec / 1000000);
+ fixup();
+ }
+
+ // explicit
+ operator long long() const {return static_cast<long long>(tv_sec) * 1000000 + tv_usec;}
+
+ xtime& operator += (xtime rhs) {
+ tv_sec += rhs.tv_sec;
+ tv_usec += rhs.tv_usec;
+ if (tv_usec >= 1000000) {
+ tv_usec -= 1000000;
+ ++tv_sec;
+ }
+ return *this;
+ }
+
+ xtime& operator -= (xtime rhs) {
+ tv_sec -= rhs.tv_sec;
+ tv_usec -= rhs.tv_usec;
+ fixup();
+ return *this;
+ }
+
+ xtime& operator %= (xtime rhs) {
+ long long t = tv_sec * 1000000 + tv_usec;
+ long long r = rhs.tv_sec * 1000000 + rhs.tv_usec;
+ t %= r;
+ tv_sec = static_cast<long>(t / 1000000);
+ tv_usec = static_cast<long>(t % 1000000);
+ fixup();
+ return *this;
+ }
+
+ friend xtime operator+(xtime x, xtime y) {return x += y;}
+ friend xtime operator-(xtime x, xtime y) {return x -= y;}
+ friend xtime operator%(xtime x, xtime y) {return x %= y;}
+
+ friend bool operator==(xtime x, xtime y)
+ { return (x.tv_sec == y.tv_sec && x.tv_usec == y.tv_usec); }
+
+ friend bool operator<(xtime x, xtime y) {
+ if (x.tv_sec == y.tv_sec)
+ return (x.tv_usec < y.tv_usec);
+ return (x.tv_sec < y.tv_sec);
+ }
+
+ friend bool operator!=(xtime x, xtime y) { return !(x == y); }
+ friend bool operator> (xtime x, xtime y) { return y < x; }
+ friend bool operator<=(xtime x, xtime y) { return !(y < x); }
+ friend bool operator>=(xtime x, xtime y) { return !(x < y); }
+
+ friend std::ostream& operator<<(std::ostream& os, xtime x)
+ {return os << '{' << x.tv_sec << ',' << x.tv_usec << '}';}
+};
+
+class xtime_clock
+{
+public:
+ typedef xtime rep;
+ typedef boost::micro period;
+ typedef boost::chrono::duration<rep, period> duration;
+ typedef boost::chrono::time_point<xtime_clock> time_point;
+
+ static time_point now();
+};
+
+xtime_clock::time_point
+xtime_clock::now()
+{
+ time_point t(duration(xtime(0)));
+ gettimeofday((timeval*)&t, 0);
+ return t;
+}
+
+void test_xtime_clock()
+{
+ using namespace boost::chrono;
+ std::cout << "timeval_demo system clock test\n";
+ std::cout << "sizeof xtime_clock::time_point = " << sizeof(xtime_clock::time_point) << '\n';
+ std::cout << "sizeof xtime_clock::duration = " << sizeof(xtime_clock::duration) << '\n';
+ std::cout << "sizeof xtime_clock::rep = " << sizeof(xtime_clock::rep) << '\n';
+ xtime_clock::duration delay(milliseconds(5));
+ xtime_clock::time_point start = xtime_clock::now();
+ while (xtime_clock::now() - start <= delay)
+ {
+ }
+ xtime_clock::time_point stop = xtime_clock::now();
+ xtime_clock::duration elapsed = stop - start;
+ std::cout << "paused " << nanoseconds(elapsed).count() << " nanoseconds\n";
+}
+
+} // timeval_demo
+
+// Handle duration with resolution not known until run time
+
+namespace runtime_resolution
+{
+
+class duration
+{
+public:
+ typedef long long rep;
+private:
+ rep rep_;
+
+ static const double ticks_per_nanosecond;
+
+public:
+ typedef boost::chrono::duration<double, boost::nano> tonanosec;
+
+ duration() {} // = default;
+ explicit duration(const rep& r) : rep_(r) {}
+
+ // conversions
+ explicit duration(const tonanosec& d)
+ : rep_(static_cast<rep>(d.count() * ticks_per_nanosecond)) {}
+
+ // explicit
+ operator tonanosec() const {return tonanosec(rep_/ticks_per_nanosecond);}
+
+ // observer
+
+ rep count() const {return rep_;}
+
+ // arithmetic
+
+ duration& operator+=(const duration& d) {rep_ += d.rep_; return *this;}
+ duration& operator-=(const duration& d) {rep_ += d.rep_; return *this;}
+ duration& operator*=(rep rhs) {rep_ *= rhs; return *this;}
+ duration& operator/=(rep rhs) {rep_ /= rhs; return *this;}
+
+ duration operator+() const {return *this;}
+ duration operator-() const {return duration(-rep_);}
+ duration& operator++() {++rep_; return *this;}
+ duration operator++(int) {return duration(rep_++);}
+ duration& operator--() {--rep_; return *this;}
+ duration operator--(int) {return duration(rep_--);}
+
+ friend duration operator+(duration x, duration y) {return x += y;}
+ friend duration operator-(duration x, duration y) {return x -= y;}
+ friend duration operator*(duration x, rep y) {return x *= y;}
+ friend duration operator*(rep x, duration y) {return y *= x;}
+ friend duration operator/(duration x, rep y) {return x /= y;}
+
+ friend bool operator==(duration x, duration y) {return x.rep_ == y.rep_;}
+ friend bool operator!=(duration x, duration y) {return !(x == y);}
+ friend bool operator< (duration x, duration y) {return x.rep_ < y.rep_;}
+ friend bool operator<=(duration x, duration y) {return !(y < x);}
+ friend bool operator> (duration x, duration y) {return y < x;}
+ friend bool operator>=(duration x, duration y) {return !(x < y);}
+};
+
+static
+double
+init_duration()
+{
+ //mach_timebase_info_data_t MachInfo;
+ //mach_timebase_info(&MachInfo);
+ //return static_cast<double>(MachInfo.denom) / MachInfo.numer;
+ return static_cast<double>(1) / 1000; // Windows FILETIME is 1 per microsec
+}
+
+const double duration::ticks_per_nanosecond = init_duration();
+
+class clock;
+
+class time_point
+{
+public:
+ typedef runtime_resolution::clock clock;
+ typedef long long rep;
+private:
+ rep rep_;
+
+
+ rep count() const {return rep_;}
+public:
+
+ time_point() : rep_(0) {}
+ explicit time_point(const duration& d)
+ : rep_(d.count()) {}
+
+ // arithmetic
+
+ time_point& operator+=(const duration& d) {rep_ += d.count(); return *this;}
+ time_point& operator-=(const duration& d) {rep_ -= d.count(); return *this;}
+
+ friend time_point operator+(time_point x, duration y) {return x += y;}
+ friend time_point operator+(duration x, time_point y) {return y += x;}
+ friend time_point operator-(time_point x, duration y) {return x -= y;}
+ friend duration operator-(time_point x, time_point y) {return duration(x.rep_ - y.rep_);}
+};
+
+class clock
+{
+public:
+ typedef duration::rep rep;
+ typedef runtime_resolution::duration duration;
+ typedef runtime_resolution::time_point time_point;
+
+ static time_point now()
+ {
+ timeval tv;
+ gettimeofday( &tv, 0 );
+ return time_point(duration((static_cast<rep>(tv.tv_sec)<<32) | tv.tv_usec));
+ }
+};
+
+void test()
+{
+ using namespace boost::chrono;
+ std::cout << "runtime_resolution test\n";
+ clock::duration delay(boost::chrono::milliseconds(5));
+ clock::time_point start = clock::now();
+ while (clock::now() - start <= delay)
+ ;
+ clock::time_point stop = clock::now();
+ clock::duration elapsed = stop - start;
+ std::cout << "paused " << nanoseconds(duration_cast<nanoseconds>(duration::tonanosec(elapsed))).count()
+ << " nanoseconds\n";
+}
+
+} // runtime_resolution
+
+// miscellaneous tests and demos:
+
+
+using namespace boost::chrono;
+
+void physics_function(duration<double> d)
+{
+ std::cout << "d = " << d.count() << '\n';
+}
+
+void drive_physics_function()
+{
+ physics_function(nanoseconds(3));
+ physics_function(hours(3));
+ physics_function(duration<double>(2./3));
+ std::cout.precision(16);
+ physics_function( hours(3) + nanoseconds(-3) );
+}
+
+void test_range()
+{
+ using namespace boost::chrono;
+ hours h1 = hours(24 * ( 365 * 292 + 292/4));
+ nanoseconds n1 = h1 + nanoseconds(1);
+ nanoseconds delta = n1 - h1;
+ std::cout << "292 years of hours = " << h1.count() << "hr\n";
+ std::cout << "Add a nanosecond = " << n1.count() << "ns\n";
+ std::cout << "Find the difference = " << delta.count() << "ns\n";
+}
+
+void test_extended_range()
+{
+ using namespace boost::chrono;
+ hours h1 = hours(24 * ( 365 * 244000 + 244000/4));
+ /*auto*/ microseconds u1 = h1 + microseconds(1);
+ /*auto*/ microseconds delta = u1 - h1;
+ std::cout << "244,000 years of hours = " << h1.count() << "hr\n";
+ std::cout << "Add a microsecond = " << u1.count() << "us\n";
+ std::cout << "Find the difference = " << delta.count() << "us\n";
+}
+
+template <class Rep, class Period>
+void inspect_duration(boost::chrono::duration<Rep, Period> d, const std::string& name)
+{
+ typedef boost::chrono::duration<Rep, Period> Duration;
+ std::cout << "********* " << name << " *********\n";
+ std::cout << "The period of " << name << " is " << (double)Period::num/Period::den << " seconds.\n";
+ std::cout << "The frequency of " << name << " is " << (double)Period::den/Period::num << " Hz.\n";
+ std::cout << "The representation is ";
+ if (boost::is_floating_point<Rep>::value)
+ {
+ std::cout << "floating point\n";
+ std::cout << "The precision is the most significant ";
+ std::cout << std::numeric_limits<Rep>::digits10 << " decimal digits.\n";
+ }
+ else if (boost::is_integral<Rep>::value)
+ {
+ std::cout << "integral\n";
+ d = Duration(Rep(1));
+ boost::chrono::duration<double> dsec = d;
+ std::cout << "The precision is " << dsec.count() << " seconds.\n";
+ }
+ else
+ {
+ std::cout << "a class type\n";
+ d = Duration(Rep(1));
+ boost::chrono::duration<double> dsec = d;
+ std::cout << "The precision is " << dsec.count() << " seconds.\n";
+ }
+ d = Duration((std::numeric_limits<Rep>::max)());
+ using namespace boost::chrono;
+ using namespace std;
+ typedef duration<double, boost::ratio_multiply<boost::ratio<24*3652425,10000>, hours::period>::type> Years;
+ Years years = d;
+ std::cout << "The range is +/- " << years.count() << " years.\n";
+ std::cout << "sizeof(" << name << ") = " << sizeof(d) << '\n';
+}
+
+void inspect_all()
+{
+ using namespace boost::chrono;
+ std::cout.precision(6);
+ inspect_duration(nanoseconds(), "nanoseconds");
+ inspect_duration(microseconds(), "microseconds");
+ inspect_duration(milliseconds(), "milliseconds");
+ inspect_duration(seconds(), "seconds");
+ inspect_duration(minutes(), "minutes");
+ inspect_duration(hours(), "hours");
+ inspect_duration(duration<double>(), "duration<double>");
+}
+
+void test_milliseconds()
+{
+ using namespace boost::chrono;
+ milliseconds ms(250);
+ ms += milliseconds(1);
+ milliseconds ms2(150);
+ milliseconds msdiff = ms - ms2;
+ if (msdiff == milliseconds(101))
+ std::cout << "success\n";
+ else
+ std::cout << "failure: " << msdiff.count() << '\n';
+}
+
+ using namespace std;
+ using namespace boost::chrono;
+
+// Example round_up utility: converts d to To, rounding up for inexact conversions
+// Being able to *easily* write this function is a major feature!
+template <class To, class Rep, class Period>
+To
+round_up(duration<Rep, Period> d)
+{
+ To result = duration_cast<To>(d);
+ if (result < d)
+ ++result;
+ return result;
+}
+
+// demonstrate interaction with xtime-like facility:
+
+using namespace boost::chrono;
+
+struct xtime
+{
+ long sec;
+ unsigned long usec;
+};
+
+template <class Rep, class Period>
+xtime
+to_xtime_truncate(duration<Rep, Period> d)
+{
+ xtime xt;
+ xt.sec = static_cast<long>(duration_cast<seconds>(d).count());
+ xt.usec = static_cast<long>(duration_cast<microseconds>(d - seconds(xt.sec)).count());
+ return xt;
+}
+
+template <class Rep, class Period>
+xtime
+to_xtime_round_up(duration<Rep, Period> d)
+{
+ xtime xt;
+ xt.sec = static_cast<long>(duration_cast<seconds>(d).count());
+ xt.usec = static_cast<unsigned long>(round_up<microseconds>(d - seconds(xt.sec)).count());
+ return xt;
+}
+
+microseconds
+from_xtime(xtime xt)
+{
+ return seconds(xt.sec) + microseconds(xt.usec);
+}
+
+void print(xtime xt)
+{
+ cout << '{' << xt.sec << ',' << xt.usec << "}\n";
+}
+
+void test_with_xtime()
+{
+ cout << "test_with_xtime\n";
+ xtime xt = to_xtime_truncate(seconds(3) + milliseconds(251));
+ print(xt);
+ milliseconds ms = duration_cast<milliseconds>(from_xtime(xt));
+ cout << ms.count() << " milliseconds\n";
+ xt = to_xtime_round_up(ms);
+ print(xt);
+ xt = to_xtime_truncate(seconds(3) + nanoseconds(999));
+ print(xt);
+ xt = to_xtime_round_up(seconds(3) + nanoseconds(999));
+ print(xt);
+}
+
+void test_system_clock()
+{
+ cout << "system_clock test" << endl;
+ system_clock::duration delay = milliseconds(5);
+ system_clock::time_point start = system_clock::now();
+ while (system_clock::now() - start <= delay)
+ ;
+ system_clock::time_point stop = system_clock::now();
+ system_clock::duration elapsed = stop - start;
+ cout << "paused " << nanoseconds(elapsed).count() << " nanoseconds\n";
+ start = system_clock::now();
+ stop = system_clock::now();
+ cout << "system_clock resolution estimate: " << nanoseconds(stop-start).count() << " nanoseconds\n";
+}
+
+void test_steady_clock()
+{
+ cout << "steady_clock test" << endl;
+ steady_clock::duration delay = milliseconds(5);
+ steady_clock::time_point start = steady_clock::now();
+ while (steady_clock::now() - start <= delay)
+ ;
+ steady_clock::time_point stop = steady_clock::now();
+ steady_clock::duration elapsed = stop - start;
+ cout << "paused " << nanoseconds(elapsed).count() << " nanoseconds\n";
+ start = steady_clock::now();
+ stop = steady_clock::now();
+ cout << "steady_clock resolution estimate: " << nanoseconds(stop-start).count() << " nanoseconds\n";
+}
+
+void test_hi_resolution_clock()
+{
+ cout << "high_resolution_clock test" << endl;
+ high_resolution_clock::duration delay = milliseconds(5);
+ high_resolution_clock::time_point start = high_resolution_clock::now();
+ while (high_resolution_clock::now() - start <= delay)
+ ;
+ high_resolution_clock::time_point stop = high_resolution_clock::now();
+ high_resolution_clock::duration elapsed = stop - start;
+ cout << "paused " << nanoseconds(elapsed).count() << " nanoseconds\n";
+ start = high_resolution_clock::now();
+ stop = high_resolution_clock::now();
+ cout << "high_resolution_clock resolution estimate: " << nanoseconds(stop-start).count() << " nanoseconds\n";
+}
+
+//void test_mixed_clock()
+//{
+// cout << "mixed clock test" << endl;
+// high_resolution_clock::time_point hstart = high_resolution_clock::now();
+// cout << "Add 5 milliseconds to a high_resolution_clock::time_point\n";
+// steady_clock::time_point mend = hstart + milliseconds(5);
+// bool b = hstart == mend;
+// system_clock::time_point sstart = system_clock::now();
+// std::cout << "Subtracting system_clock::time_point from steady_clock::time_point doesn't compile\n";
+//// mend - sstart; // doesn't compile
+// cout << "subtract high_resolution_clock::time_point from steady_clock::time_point"
+// " and add that to a system_clock::time_point\n";
+// system_clock::time_point send = sstart + duration_cast<system_clock::duration>(mend - hstart);
+// cout << "subtract two system_clock::time_point's and output that in microseconds:\n";
+// microseconds ms = send - sstart;
+// cout << ms.count() << " microseconds\n";
+//}
+//
+//void test_c_mapping()
+//{
+// cout << "C map test\n";
+// using namespace boost::chrono;
+// system_clock::time_point t1 = system_clock::now();
+// std::time_t c_time = system_clock::to_time_t(t1);
+// std::tm* tmptr = std::localtime(&c_time);
+// std::cout << "It is now " << tmptr->tm_hour << ':' << tmptr->tm_min << ':' << tmptr->tm_sec << ' '
+// << tmptr->tm_year + 1900 << '-' << tmptr->tm_mon + 1 << '-' << tmptr->tm_mday << '\n';
+// c_time = std::mktime(tmptr);
+// system_clock::time_point t2 = system_clock::from_time_t(c_time);
+// microseconds ms = t1 - t2;
+// std::cout << "Round-tripping through the C interface truncated the precision by " << ms.count() << " microseconds\n";
+//}
+
+void test_duration_division()
+{
+ cout << hours(3) / milliseconds(5) << '\n';
+ cout << milliseconds(5) / hours(3) << '\n';
+ cout << hours(1) / milliseconds(1) << '\n';
+}
+
+namespace I_dont_like_the_default_duration_behavior
+{
+
+// Here's how you override the duration's default constructor to do anything you want (in this case zero)
+
+template <class R>
+class zero_default
+{
+public:
+ typedef R rep;
+
+private:
+ rep rep_;
+public:
+ zero_default(rep i = 0) : rep_(i) {}
+ operator rep() const {return rep_;}
+
+ zero_default& operator+=(zero_default x) {rep_ += x.rep_; return *this;}
+ zero_default& operator-=(zero_default x) {rep_ -= x.rep_; return *this;}
+ zero_default& operator*=(zero_default x) {rep_ *= x.rep_; return *this;}
+ zero_default& operator/=(zero_default x) {rep_ /= x.rep_; return *this;}
+
+ zero_default operator+ () const {return *this;}
+ zero_default operator- () const {return zero_default(-rep_);}
+ zero_default& operator++() {++rep_; return *this;}
+ zero_default operator++(int) {return zero_default(rep_++);}
+ zero_default& operator--() {--rep_; return *this;}
+ zero_default operator--(int) {return zero_default(rep_--);}
+
+ friend zero_default operator+(zero_default x, zero_default y) {return x += y;}
+ friend zero_default operator-(zero_default x, zero_default y) {return x -= y;}
+ friend zero_default operator*(zero_default x, zero_default y) {return x *= y;}
+ friend zero_default operator/(zero_default x, zero_default y) {return x /= y;}
+
+ friend bool operator==(zero_default x, zero_default y) {return x.rep_ == y.rep_;}
+ friend bool operator!=(zero_default x, zero_default y) {return !(x == y);}
+ friend bool operator< (zero_default x, zero_default y) {return x.rep_ < y.rep_;}
+ friend bool operator<=(zero_default x, zero_default y) {return !(y < x);}
+ friend bool operator> (zero_default x, zero_default y) {return y < x;}
+ friend bool operator>=(zero_default x, zero_default y) {return !(x < y);}
+};
+
+typedef boost::chrono::duration<zero_default<long long>, boost::nano > nanoseconds;
+typedef boost::chrono::duration<zero_default<long long>, boost::micro > microseconds;
+typedef boost::chrono::duration<zero_default<long long>, boost::milli > milliseconds;
+typedef boost::chrono::duration<zero_default<long long> > seconds;
+typedef boost::chrono::duration<zero_default<long long>, boost::ratio<60> > minutes;
+typedef boost::chrono::duration<zero_default<long long>, boost::ratio<3600> > hours;
+
+void test()
+{
+ milliseconds ms;
+ cout << ms.count() << '\n';
+}
+
+} // I_dont_like_the_default_duration_behavior
+
+// Build a min for two time_points
+
+template <class Rep, class Period>
+void
+print_duration(ostream& os, duration<Rep, Period> d)
+{
+ os << d.count() << " * " << Period::num << '/' << Period::den << " seconds\n";
+}
+
+// Example min utility: returns the earliest time_point
+// Being able to *easily* write this function is a major feature!
+template <class Clock, class Duration1, class Duration2>
+inline
+typename boost::common_type<time_point<Clock, Duration1>,
+ time_point<Clock, Duration2> >::type
+min BOOST_PREVENT_MACRO_SUBSTITUTION (time_point<Clock, Duration1> t1, time_point<Clock, Duration2> t2)
+{
+ return t2 < t1 ? t2 : t1;
+}
+
+void test_min()
+{
+ typedef time_point<system_clock,
+ boost::common_type<system_clock::duration, seconds>::type> T1;
+ typedef time_point<system_clock,
+ boost::common_type<system_clock::duration, nanoseconds>::type> T2;
+ typedef boost::common_type<T1, T2>::type T3;
+ /*auto*/ T1 t1 = system_clock::now() + seconds(3);
+ /*auto*/ T2 t2 = system_clock::now() + nanoseconds(3);
+ /*auto*/ T3 t3 = (min)(t1, t2);
+ print_duration(cout, t1 - t3);
+ print_duration(cout, t2 - t3);
+}
+
+void explore_limits()
+{
+ typedef duration<long long, boost::ratio_multiply<boost::ratio<24*3652425,10000>,
+ hours::period>::type> Years;
+ steady_clock::time_point t1( Years(250));
+ steady_clock::time_point t2(-Years(250));
+ // 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);
+ cout << d.count() << " microseconds\n";
+}
+
+void manipulate_clock_object(system_clock clock)
+{
+ system_clock::duration delay = milliseconds(5);
+ system_clock::time_point start = clock.now();
+ while (clock.now() - start <= delay)
+ ;
+ system_clock::time_point stop = clock.now();
+ system_clock::duration elapsed = stop - start;
+ cout << "paused " << nanoseconds(elapsed).count() << " nanoseconds\n";
+};
+
+template <long long speed>
+struct cycle_count
+{
+ typedef typename boost::ratio_multiply<boost::ratio<speed>, boost::mega>::type frequency; // Mhz
+ typedef typename boost::ratio_divide<boost::ratio<1>, frequency>::type period;
+ typedef long long rep;
+ typedef boost::chrono::duration<rep, period> duration;
+ typedef boost::chrono::time_point<cycle_count> time_point;
+
+ static time_point now()
+ {
+ static long long tick = 0;
+ // return exact cycle count
+ return time_point(duration(++tick)); // fake access to clock cycle count
+ }
+};
+
+template <long long speed>
+struct approx_cycle_count
+{
+ static const long long frequency = speed * 1000000; // MHz
+ typedef nanoseconds duration;
+ typedef duration::rep rep;
+ typedef duration::period period;
+ static const long long nanosec_per_sec = period::den;
+ typedef boost::chrono::time_point<approx_cycle_count> time_point;
+
+ static time_point now()
+ {
+ static long long tick = 0;
+ // return cycle count as an approximate number of nanoseconds
+ // compute as if nanoseconds is only duration in the std::lib
+ return time_point(duration(++tick * nanosec_per_sec / frequency));
+ }
+};
+
+void cycle_count_delay()
+{
+ {
+ typedef cycle_count<400> clock;
+ cout << "\nSimulated " << clock::frequency::num / boost::mega::num << "MHz clock which has a tick period of "
+ << duration<double, boost::nano>(clock::duration(1)).count() << " nanoseconds\n";
+ nanoseconds delayns(500);
+ clock::duration delay = duration_cast<clock::duration>(delayns);
+ cout << "delay = " << delayns.count() << " nanoseconds which is " << delay.count() << " cycles\n";
+ clock::time_point start = clock::now();
+ clock::time_point stop = start + delay;
+ while (clock::now() < stop) // no multiplies or divides in this loop
+ ;
+ clock::time_point end = clock::now();
+ clock::duration elapsed = end - start;
+ cout << "paused " << elapsed.count() << " cycles ";
+ cout << "which is " << duration_cast<nanoseconds>(elapsed).count() << " nanoseconds\n";
+ }
+ {
+ typedef approx_cycle_count<400> clock;
+ cout << "\nSimulated " << clock::frequency / 1000000 << "MHz clock modeled with nanoseconds\n";
+ clock::duration delay = nanoseconds(500);
+ cout << "delay = " << delay.count() << " nanoseconds\n";
+ clock::time_point start = clock::now();
+ clock::time_point stop = start + delay;
+ while (clock::now() < stop) // 1 multiplication and 1 division in this loop
+ ;
+ clock::time_point end = clock::now();
+ clock::duration elapsed = end - start;
+ cout << "paused " << elapsed.count() << " nanoseconds\n";
+ }
+ {
+ typedef cycle_count<1500> clock;
+ cout << "\nSimulated " << clock::frequency::num / boost::mega::num << "MHz clock which has a tick period of "
+ << duration<double, boost::nano>(clock::duration(1)).count() << " nanoseconds\n";
+ nanoseconds delayns(500);
+ clock::duration delay = duration_cast<clock::duration>(delayns);
+ cout << "delay = " << delayns.count() << " nanoseconds which is " << delay.count() << " cycles\n";
+ clock::time_point start = clock::now();
+ clock::time_point stop = start + delay;
+ while (clock::now() < stop) // no multiplies or divides in this loop
+ ;
+ clock::time_point end = clock::now();
+ clock::duration elapsed = end - start;
+ cout << "paused " << elapsed.count() << " cycles ";
+ cout << "which is " << duration_cast<nanoseconds>(elapsed).count() << " nanoseconds\n";
+ }
+ {
+ typedef approx_cycle_count<1500> clock;
+ cout << "\nSimulated " << clock::frequency / 1000000 << "MHz clock modeled with nanoseconds\n";
+ clock::duration delay = nanoseconds(500);
+ cout << "delay = " << delay.count() << " nanoseconds\n";
+ clock::time_point start = clock::now();
+ clock::time_point stop = start + delay;
+ while (clock::now() < stop) // 1 multiplication and 1 division in this loop
+ ;
+ clock::time_point end = clock::now();
+ clock::duration elapsed = end - start;
+ cout << "paused " << elapsed.count() << " nanoseconds\n";
+ }
+}
+
+void test_special_values()
+{
+ std::cout << "duration<unsigned>::min().count() = " << (duration<unsigned>::min)().count() << '\n';
+ std::cout << "duration<unsigned>::zero().count() = " << duration<unsigned>::zero().count() << '\n';
+ std::cout << "duration<unsigned>::max().count() = " << (duration<unsigned>::max)().count() << '\n';
+ std::cout << "duration<int>::min().count() = " << (duration<int>::min)().count() << '\n';
+ std::cout << "duration<int>::zero().count() = " << duration<int>::zero().count() << '\n';
+ std::cout << "duration<int>::max().count() = " << (duration<int>::max)().count() << '\n';
+}
+
+int main()
+{
+ basic_examples();
+ testStdUser();
+ testUser1();
+ testUser2();
+ drive_physics_function();
+ test_range();
+ test_extended_range();
+ inspect_all();
+ test_milliseconds();
+ test_with_xtime();
+ test_system_clock();
+ test_steady_clock();
+ test_hi_resolution_clock();
+ //test_mixed_clock();
+ timeval_demo::test_xtime_clock();
+ runtime_resolution::test();
+ //test_c_mapping();
+ test_duration_division();
+ I_dont_like_the_default_duration_behavior::test();
+ test_min();
+ inspect_duration(common_type<duration<double>, hours, microseconds>::type(),
+ "common_type<duration<double>, hours, microseconds>::type");
+ explore_limits();
+ manipulate_clock_object(system_clock());
+ duration<double, boost::milli> d = milliseconds(3) * 2.5;
+ inspect_duration(milliseconds(3) * 2.5, "milliseconds(3) * 2.5");
+ cout << d.count() << '\n';
+// milliseconds ms(3.5); // doesn't compile
+ cout << "milliseconds ms(3.5) doesn't compile\n";
+ cycle_count_delay();
+ test_special_values();
+ return 0;
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 10:33:41 +0000