$include_dir="/home/hyper-archives/boost-commit/include"; include("$include_dir/msg-header.inc") ?>
From: hinnant_at_[hidden]
Date: 2007-12-07 13:59:29
Author: hinnant
Date: 2007-12-07 13:59:29 EST (Fri, 07 Dec 2007)
New Revision: 41829
URL: http://svn.boost.org/trac/boost/changeset/41829
Log:
merged date_time branch
Text files modified: 
   sandbox/committee/LWG/ref_impl/hdate_time |     4                                         
   sandbox/committee/LWG/thread_library.html |  2218 ++++++++++++--------------------------- 
   2 files changed, 692 insertions(+), 1530 deletions(-)
Modified: sandbox/committee/LWG/ref_impl/hdate_time
==============================================================================
--- sandbox/committee/LWG/ref_impl/hdate_time	(original)
+++ sandbox/committee/LWG/ref_impl/hdate_time	2007-12-07 13:59:29 EST (Fri, 07 Dec 2007)
@@ -238,7 +238,7 @@
         typedef long long tick_type;
     
         system_time();
-        system_time(time_t secs, nanoseconds ns);
+        system_time(time_t secs, nanoseconds ns = 0);
     
         time_t seconds_since_epoch() const;
         nanoseconds nanoseconds_since_epoch() const;
@@ -1461,7 +1461,7 @@
 public:
 
     system_time() : ns_(0) {}
-    system_time(time_t secs, nanoseconds ns)
+    system_time(time_t secs, nanoseconds ns = 0)
         : ns_(secs * 1000000000LL + ns.count()) {}
 
     // ~system_time() = default;
Modified: sandbox/committee/LWG/thread_library.html
==============================================================================
--- sandbox/committee/LWG/thread_library.html	(original)
+++ sandbox/committee/LWG/thread_library.html	2007-12-07 13:59:29 EST (Fri, 07 Dec 2007)
@@ -29,7 +29,7 @@
 <h1>Multi-threading Library for Standard C++</h1>
 
 <p>
-ISO/IEC JTC1 SC22 WG21 N???? = 07-???? - 2007-12-04
+ISO/IEC JTC1 SC22 WG21 N???? = 07-???? - 2007-12-07
 </p>
 
 <p>
@@ -94,15 +94,16 @@
 <br>        30.4.1 Class condition_variable [thread.condvar]
 <br>        30.4.2 Class condition_variable_any [thread.condvarany]
 <br>Chapter 31   Date Time Library [time]
-<br>    31.1 Class system_time [time.system]
-<br>    31.2 Function get_system_time [time.getsystem]
-<br>    31.3 Common Duration Functions [time.duration]
-<br>    31.4 Class nanoseconds [time.nanoseconds]
-<br>    31.5 Class microseconds [time.microseconds]
-<br>    31.6 Class milliseconds [time.milliseconds]
-<br>    31.7 Class seconds [time.seconds]
-<br>    31.8 Class minutes [time.minutes]
-<br>    31.9 Class hours [time.hours]
+<br>    31.1 Duration Requirements [time.duration.requirements]
+<br>    31.2 Class nanoseconds [time.nanoseconds]
+<br>    31.3 Class microseconds [time.microseconds]
+<br>    31.4 Class milliseconds [time.milliseconds]
+<br>    31.5 Class seconds [time.seconds]
+<br>    31.6 Class minutes [time.minutes]
+<br>    31.7 Class hours [time.hours]
+<br>    31.8 Class system_time [time.system]
+<br>    <a href="#time.nonmembers">31.9 Non-member functions 
+[time.nonmembers]</a>
 <br>References
 <br>Acknowledgments
 </p>
@@ -3450,20 +3451,22 @@
 in the time continuum.
 A <dfn>time duration</dfn> represents a length of time
 unattached to any time point.
-Time points and time durations have a <dfn>resolution</dfn>,
-which is their smallest representable time duration.
+Time points and time durations have a
+<dfn>resolution</dfn> which is their smallest representable time duration.
 Time points
 have an <dfn>epoch</dfn> or start of a given time scale.
-For time_t the epoch is
-1970-01-01 00:00:00.
-</p>
+<i>[Example: </i>For std::time_t the epoch is
+1970-01-01 00:00:00. <i>--end example]</i></p>
 
 <p>
 Throughout this clause, the names of template parameters are used to express
-type requirements.
-<b>[Someone:
-Define Duration, RhsDuration.
-]</b>
+type requirements. Parameter names <code>Duration</code>, <code>LhsDuration</code>
+and <code>RhsDuration</code> express the 
+Duration ([<a name="time.duration">[time.duration.requirements]</a>]) 
+requirements.
+For all non-member functions in this clause which are templated on Duration types,
+the implementation shall constrain these function templates such that they will
+only instantiate for Duration types.
 </p>
 
 <p>
@@ -3475,2006 +3478,1165 @@
 namespace std {
 
 // <em>duration types</em>
-class hours;
-class minutes;
-class seconds;
-class milliseconds;
-class microseconds;
 class nanoseconds;
+class microseconds;
+class milliseconds;
+class seconds;
+class minutes;
+class hours;
 
-// <em>timepoint</em>
+// <em>timepoint type</em>
 class system_time;
 
-// <em>functions</em>
+// <em>non-member functions </em></code>[time.nonmembers]<code>
 system_time get_system_time();
 
-}  // std
-</code></pre>
-</blockquote>
-
-<h3><a name="time.system">31.1 Class system_time [time.system]</a></h3>
-
-<p>
-The class <code>system_time</code> provides a time point
-that represents the current
-Coordinated Universal Time, known as UTC, time.
-<code>system_time</code>
-shall provide an epoch time of 1970-01-01 00:00:00.000000000
-and a maximum time value of at least epoch time + 292 years.
-</p>
-
-<p>
-<b>[Crowl:
-I hope I'm not getting too pedantic here,
-but I'd recommend encuraging a "system time" based on UTC
-rather than on defining it so.
-The reason is that embedded systems
-need to function independent of the global time system
-when lives are at stake.
-I don't want the flight control software dependent on UTC.
-]</b>
-</p>
-
-<p>
-class <code>system_time</code> shall be EqualityComparable, LessThanComparable,
-CopyConstructable, DefaultConstructable, and Assignable.
-</p>
-
-<blockquote>
-<pre><code>
-class system_time
-{
-public:
-
-    system_time();
-    system_time(time_t, nanoseconds ns);
-    ~system_time();
-
-    time_t seconds_since_epoch() const;
-    nanoseconds nanoseconds_since_epoch() const;
-
-    // <em>traits</em>
-    typedef <var><strong>implementation-defined</strong></var> tick_type;
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
-
-    // <em>comparison functions</em>
-    bool operator==(const system_time& rhs) const;
-    bool operator!=(const system_time& rhs) const;
-    bool operator>(const system_time& rhs) const;
-    bool operator>=(const system_time& rhs) const;
-    bool operator<(const system_time& rhs) const;
-    bool operator<=(const system_time& rhs) const;
-
-    // <em>arithmetic functions</em>
-    nanoseconds operator-(const system_time& rhs) const
-
-    template<typename Duration>
-    system_time operator+(const Duration& td) const;
-
-    template<typename Duration>
-    system_time& operator+=(const Duration& td);
+template<typename Duration>
+  system_time operator+(const Duration& td, const system_time& rhs);
 
-    template<typename Duration>
-    system_time operator-(const Duration& td) const;
+template <class LhsDuration, class RhsDuration>
+  bool operator==(const LhsDuration& lhs, const RhsDuration& rhs);
+template <class LhsDuration, class RhsDuration>
+  bool operator!=(const LhsDuration& lhs, const RhsDuration& rhs);
+
+template <class LhsDuration, class RhsDuration>
+  bool operator< (const LhsDuration& lhs, const RhsDuration& rhs);
+template <class LhsDuration, class RhsDuration>
+  bool operator<=(const LhsDuration& lhs, const RhsDuration& rhs);
+template <class LhsDuration, class RhsDuration>
+  bool operator> (const LhsDuration& lhs, const RhsDuration& rhs);
+template <class LhsDuration, class RhsDuration>
+  bool operator>=(const LhsDuration& lhs, const RhsDuration& rhs);
+
+template <class LhsDuration, class RhsDuration>
+  <i>FRDuration</i> operator+(const LhsDuration& lhs, const RhsDuration& rhs)
+template <class LhsDuration, class RhsDuration>
+  <i>FRDuration</i> operator-(const LhsDuration& lhs, const RhsDuration& rhs)
 
-    template<typename Duration>
-    system_time& operator-=(const Duration& td)
+template <class Duration>
+  Duration operator*(Duration lhs, long rhs)
+template <class Duration>
+  Duration operator*(long lhs, Duration rhs)
 
-};
-</code></pre>
+template <class Duration>
+  Duration operator/(Duration lhs, long rhs)
+}  // std</code></pre>
 </blockquote>
 
-<p>
-[<i>Note:</i>
-292 years represents the number of nanoseconds
-that can be represented in a signed 64 bit integer.
-—<i>end note</i>]
+<p>Type <i><code>FRDuration</code> </i>is whichever of <code>LhsDuration</code> 
+or <code>RhsDuration</code> has the finest resolution. If their 
+resolutions are the same, <i><code>FRDuration</code> </i>is <code>LhsDuration</code>.</p>
+
+<p>Unless otherwise specified, no function in this clause shall throw 
+exceptions. <i>[Note: </i>Such blanket prohibition of exceptions is unusual in 
+the standard library, but without the prohibition time-related code becomes 
+littered with excessive try-catch blocks. These functions are also unusual in 
+that they encompass virtually no cases where errors can be detected and 
+reported.  <i>--end note.]</i></p>
+
+<h3><a name="time.duration.requirements">31.1 Duration requirements 
+[time.duration.requirements]</a></h3>
+<p>This subclause describes requirements on duration types used to instantiate 
+templates defined in the C++ Standard Library.</p>
+<p>Objects of duration types provide relative time values and comparison and 
+arithmetic operations on those values.</p>
+<p>Template definitions in the C++ Standard Library refer to the named Duration 
+requirements for duration types whose details are specified below.</p>
+<p>A duration type shall be EqualityComparable, LessThanComparable, 
+CopyConstructible, DefaultConstructible, CopyAssignable, Swappable, and 
+Destructible.  In addition, it must meet the requirements for well-defined 
+expressions specified it the following table, where <code>D</code> and <code>E</code> 
+are duration types, <code>d</code> denotes a <code>const</code> value of type
+<code>D</code>, <code>e</code> denotes a <code>const</code> value of type <code>
+E</code>, <code>c</code> denotes a <code>long</code> value.
+The resolution of <code>E</code> shall not be finer than the resolution of <code>D</code>
+(diagnostic required).
 </p>
+<table style="border-collapse: collapse;" border="1" bordercolor="#111111" cellpadding="5" cellspacing="0" width="100%">
+  <tr>
+    <td width="25%"><b><i>expression</i></b></td>
+    <td width="11%"><b><i>return type</i></b></td>
+    <td width="39%"><b><i>return value or other requirement</i></b></td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>D::tick_type</code></td>
+    <td width="11%"><i><b>implementation-defined</b></i></td>
+    <td width="39%"> </td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>D::ticks_per_second;</code></td>
+    <td valign="top" width="11%"><code>D::tick_type</code></td>
+    <td valign="top" width="39%">The number of ticks per 
+    second, or 0 for types for which the number of ticks per second is less than 1. </td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>D::seconds_per_tick;</code></td>
+    <td valign="top" width="11%"><code>D::tick_type</code></td>
+    <td valign="top" width="39%">The number of seconds per 
+    tick, or 0 for types for which the number of seconds per tick is less than 1. </td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>D::is_subsecond;</code></td>
+    <td valign="top" width="11%"><code>bool</code></td>
+    <td valign="top" width="39%"><code>seconds_per_tick == 0</code>. </td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>d.count();</code></td>
+    <td valign="top" width="11%"><code>D::tick_type</code></td>
+    <td valign="top" width="39%">The most recent value established by a 
+    non-const function's <i>Postcondition</i>.</td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>-d;</code></td>
+    <td valign="top" width="11%"><code>D</code></td>
+    <td valign="top" width="39%"><code>D(-d.tick_count())</code></td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>d -= e</code></td>
+    <td valign="top" width="11%"><code>D&</code></td>
+    <td valign="top" width="39%"><i>Postcondition:</i><code> d.tick_count == 
+    d.tick_count()</code><sub>at-entry</sub><code>-x</code>, where <code>x</code> 
+    is <code>e.tick_count()</code> converted to the resolution of <code>D</code>.</td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>d += e</code></td>
+    <td valign="top" width="11%"><code>D&</code></td>
+    <td valign="top" width="39%"><i>Postcondition:</i><code> d.tick_count == 
+    d.tick_count()</code><sub>at-entry</sub><code>+x</code>, where <code>x</code> 
+    is <code>e.tick_count()</code> converted to the resolution of <code>D</code>.</td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>d /= c</code></td>
+    <td valign="top" width="11%"><code>D&</code></td>
+    <td valign="top" width="39%"><i>Postcondition:</i> <code>d.tick_count() == 
+    d.tick_count()</code><sub>at-entry</sub><code>/c</code></td>
+  </tr>
+  <tr>
+    <td valign="top" width="25%"><code>d *= c</code></td>
+    <td valign="top" width="11%"><code>D&</code></td>
+    <td valign="top" width="39%"><i>Postcondition:</i>  <code>d.tick_count() 
+    == d.tick_count()</code><sub>at-entry</sub><code>*c</code></td>
+  </tr>
+</table>
 
-<pre><code>
-system_time();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Constructs a system_time
-object representing the epoch time point 1970-01-01 00:00:00.000000000
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-system_time(time_t secs, nanoseconds ns);
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Construct<var>s</var> a utc
-time object representing the time point
-that is secs + 1,000,000,000*ns after the epoch.
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-If the total nanoseconds > 1 second the seconds are
-incremented appropriately.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-time_t seconds_since_epoch() const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-The count of seconds since the epoch time.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-nanoseconds nanoseconds_since_epoch() const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-The count of nanoseconds
-since the epoch time.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-static tick_type ticks_per_second();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-1000000000
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-0
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-Since this is a subsecond type it returns 0 for seconds_per_tick.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-static bool is_subsecond();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-true.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-bool operator==(const system_time& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if
-the time
-represented by <code>*this</code> is equal to the time represented by <var>rhs</var>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-bool operator!=(const system_time& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if the time represented by <code>*this</code> is not equal to the time represented
-by <var>rhs</var>.
-</dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
+<h3><a name="time.nanoseconds">32.2 Class nanoseconds [time.nanoseconds]</a></h3>
 
-<pre><code>
-bool operator>(const system_time& rhs) const;
-</code></pre>
+<p>
+Objects of class <code>nanoseconds</code> can be used to represent a count of nanoseconds. 
+Class <code>nanoseconds</code> shall be a duration type ([time.duration.requirements]). 
+For the sake of exposition, the semantics of member functions are not described 
+if they have the same apparent semantics as specified for duration types.</p>
 
 <blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if time represented by
-<code>*this</code> is greater than the time represented by <var>rhs</var>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
 <pre><code>
-bool operator>=(const system_time& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if time represented
-by <code>*this</code> is greater or equal than the time represented by <var>rhs</var>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
+class nanoseconds
+{
+public:
+    // <em>traits information</em>
+    typedef <var><strong>implementation-defined</strong></var> tick_type;
+    static const tick_type ticks_per_second = 1000000000;
+    static const tick_type seconds_per_tick = 0;
+    static const bool is_subsecond = true;
+
+    // <i>construct/copy/destroy functions</i>
+    nanoseconds(long long ns=0);
+    nanoseconds(nanoseconds&&);
+    nanoseconds& operator=(nanoseconds&&);
 
-<pre><code>
-bool operator<(const system_time& rhs) const;
-</code></pre>
+    // <em>observer functions</em>
+    tick_type count() const;
 
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if time represented by <code>*this</code>
-is less than the time represented by <var>rhs</var>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-bool operator<=(const system_time& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if time represented by <code>*this</code>
-is less or equal than the time represented by <var>rhs</var>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-nanoseconds operator-(const system_time& <var>rhs</var>) const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-The difference in nanoseconds between
-the time represented by <code>*this</code> and
-the time represented by <code><var>rhs</var></code>.
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-If rhs is greater the result will be a negative nanosecond.
-count.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename Duration>
-system_time operator+(const Duration& td) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-The duration converted to nanosecond resolution
-and added to the time represented by <code>*this</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename Duration>
-system_time& operator+=(const Duration& td);
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Convert the duration to nanosecond resolution
-and add it to the time represented by <code>*this</code>.
-</dd>
-
-<dt>Returns:</dt>
-<dd>
-Modified value of this.
-<b>[Crowl: not a reference to this?]</b>
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename Duration>
-system_time operator-(const Duration& td) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-The duration converted to nanosecond resolution
-and subtracted from the time represented by <code>*this</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename Duration>
-system_time& operator-=(const Duration& td)
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Convert the duration to nanosecond resolution
-and subtract it from the time represented by <code>*this</code>.
-</dd>
-
-<dt>Returns:</dt>
-<dd>
-Modified value of this.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-
-<h3><a name="time.getsystem">31.2 Function get_system_time [time.getsystem]</a></h3>
-
-<p>
-The function <code>get_system_time</code>
-provides access to the system clock at a
-resolution up to nanoseconds.
-The actual resolution may vary from platform to platform.
-</p>
-
-<blockquote>
-<pre><code>
-system_time get_system_time();
-</code></pre>
-</blockquote>
-
-
-<p>
-[<b>Comment:</b>
-Typical personal computer platforms currently achieve microsecond level
-resolution from calls to the clock.
-The
-<a href="http://www.boost.org/libs/date_time/index.html">
-Boost Date-Time Library</a>
-has a class that portably implements the proposed interface,
-but it uses different C-level interfaces depending on the operating
-system.
-—<b>end comment</b>]
-</p>
-
-<h3><a name="time.duration">31.3 Common Duration Functions [time.duration]</a></h3>
-
-<p>
-The following functions are common functions to all durations types.
-These
-functions provide the basis
-for durations to be EqualityComparable, LessThanComparable
-as well arithmetic operations.
-</p>
-
-<p>
-In the following text duration_type refers to the containing duration type.
-</p>
-
-<p>
-All duration types are EqualityComparable, LessThanComparable,
-CopyConstructable, DefaultConstructable, and Assignable for duration
-objects of the same type.
-</p>
-
-<blockquote>
-<pre><code>
-class Duration {
-
-    // <em>traits information</em>
-    typedef <var><strong>implementation-defined</strong></var> tick_type;
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
-
-    // <em>comparison operators</em>
-    template<typename RhsDuration>
-    bool operator<  (const RhsDuration&) const;
-
-    template<typename RhsDuration>
-    bool operator<= (const RhsDuration&) const;
-
-    template<typename RhsDuration>
-    bool operator>  (const RhsDuration&) const;
-
-    template<typename RhsDuration>
-    bool operator>= (const RhsDuration&) const;
-
-    template<typename RhsDuration>
-    bool operator== (const RhsDuration&) const;
-
-    template<typename RhsDuration>
-    bool operator!= (const RhsDuration&) const;
-
-
-    // <em>sign inversion</em>
-    Duration operator-() const
-
-    // <em>arithmetic operations</em>
-    template<typename RhsDuration>
-    Duration operator- (const RhsDuration& d) const
-
-    template<typename RhsDuration>
-    Duration operator-=(const RhsDuration& d)
-
-    template<typename RhsDuration>
-    Duration operator+ (const RhsDuration& d) const
-
-    template<typename RhsDuration>
-    Duration operator+=(const RhsDuration& d)
-
-    Duration operator/ (int divisor) const
-    Duration operator/=(int divisor)
-    Duration operator* (int rhs) const
-    Duration operator*=(int divisor)
-
-    tick_type get_count() const
-
-}
-</code></pre>
-</blockquote>
-
-<pre><code>
-static tick_type ticks_per_second();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-A constant defined separately for each <tt>Duration</tt> type
-indicating the number of ticks per second
-(or 0 for types that are not <code>is_subsecond</code>).
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-A constant defined separately for each <tt>Duration</tt> type
-indicating the number of seconds per tick
-(or 0 for types that are <code>is_subsecond</code>).
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-static bool is_subsecond();
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-<code>true</code> if the resolution of this Duration is finer than 1 second,
-and otherwise <code>false</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-bool operator==(const RhsDuration& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if rhs duration is greater.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-bool operator!=(const RhsDuration& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if rhs is not the same time.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-bool operator>(const RhsDuration& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if the rhs duration is larger.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-bool operator>=(const RhsDuration& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if greater or equal than the rhs duration.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-bool operator<(const RhsDuration& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if less than the rhs duration.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-bool operator<=(const RhsDuration& rhs) const;
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-True if less or equal to the rhs duration.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-// <em>sign inversion</em>
-Duration operator-() const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-Negated value of the duration.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-// <em>arithmetic operations</em>
-template<typename RhsDuration>
-Duration operator- (const RhsDuration& d) const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-A duration value equal to this-rhs_duration.
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-This will fail to compile
-if the <code>RhsDuration</code> is of finer resolution than <code>*this</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-Duration operator-=(const RhsDuration& <var>d</var>)
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Modifies the value to <code>*this-<var>d</var></code>.
-</dd>
-
-<dt>Returns:</dt>
-<dd>
-<p>
-<code>this</code>
-<b>[Crowl: but this statement is inconsistent with the declaration!]</b>
-</p>
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-This will fail to compile
-if the <code>RhsDuration</code> is of finer resolution
-than <code>*this</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-Duration operator+ (const RhsDuration& d) const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-<p>
-Duration equal to this+rhs_duration.
-</p>
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-This will fail to compile
-if the <code>RhsDuration</code> is of finer resolution
-than <code>*this</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-template<typename RhsDuration>
-Duration operator+=(const RhsDuration& d)
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Modifies to value equal to this+rhs_duration.
-</dd>
-
-<dt>Returns:</dt>
-<dd>
-<p>
-this
-</p>
-</dd>
-
-<dt>Remarks:</dt>
-<dd>
-This will fail to compile
-if the <code>RhsDuration</code> is of finer resolution
-than <code>*this</code>.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-Duration operator/ (int divisor) const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-Duration with value equal to this/divisor according to
-integer arithmetic rules.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-Duration operator/=(int divisor)
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Change value of this by this/divisor according to integer
-arithmetic rules.
-</dd>
-
-<dt>Returns:</dt>
-<dd>
-this
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-Duration operator* (int rhs) const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-Duration with value equal to this*rhs
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-Duration operator*=(int rhs)
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Modifies to value equal to this*rhs.
-</dd>
-
-<dt>Returns:</dt>
-<dd>
-this
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
+<i>    // modifier functions</i>
+    template<typename RhsDuration>
+        nanoseconds& operator-=(const RhsDuration& d);
+    template<typename RhsDuration>
+        nanoseconds& operator+=(const RhsDuration& d);
+    nanoseconds& operator*=(long multiplier);
+    nanoseconds& operator/=(long divisor);
+
+    // <i>operations</i>
+    nanoseconds operator-() const;
+};</code></pre>
 </blockquote>
 
 <pre><code>
-tick_type get_count() const
-</code></pre>
+nanoseconds(long long ns=0);</code></pre>
 
 <blockquote>
 <dl>
-<dt>Returns:</dt>
+<dt>Effects:</dt>
 <dd>
-The count at the resolution of the time duration type.
+Constructs an object of type <code>nanoseconds</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
+<dt>Postcondition:</dt>
+<dd><code>count() == ns;</code></dd>
 </dl>
 </blockquote>
 
-<h3><a name="time.nanoseconds">31.4 Class nanoseconds [time.nanoseconds]</a></h3>
+<h3><a name="time.microseconds">32.3 Class microseconds [time.microseconds]</a></h3>
 
 <p>
-Objects of class <code>nanoseconds</code> can be used to represent a count of nanoseconds.
-</p>
+Objects of class <code>microseconds</code> can be used to represent a count of microseconds. 
+Class <code>microseconds</code> shall be a duration type ([time.duration.requirements]). 
+For the sake of exposition, the semantics of member functions are not described 
+if they have the same apparent semantics as specified for duration types.</p>
 
 <blockquote>
 <pre><code>
-class nanoseconds
+class microseconds
 {
 public:
-
-    nanoseconds(long long=0);
-    nanoseconds(const nanoseconds& rhs);
-    ~nanoseconds();
-
     // <em>traits information</em>
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
     typedef <var><strong>implementation-defined</strong></var> tick_type;
+    static const tick_type ticks_per_second = 1000000;
+    static const tick_type seconds_per_tick = 0;
+    static const bool is_subsecond = true;
+
+    // <i>construct/copy/destroy functions</i>
+    microseconds(long long us=0);
+    microseconds(microseconds&&);
+    microseconds& operator=(microseconds&&);
 
-    // <em>+ common functions</em>
+    // <em>observer functions</em>
+    tick_type count() const;
 
-};
-</code></pre>
+<i>    // modifier functions</i>
+    template<typename RhsDuration>
+        microseconds& operator-=(const RhsDuration& d);
+    template<typename RhsDuration>
+        microseconds& operator+=(const RhsDuration& d);
+    microseconds& operator*=(long multiplier);
+    microseconds& operator/=(long divisor);
+
+    // <i>operations</i>
+    microseconds operator-() const;
+
+    // <em>conversions</em>
+    operator nanoseconds() const;
+};</code></pre>
 </blockquote>
 
-<pre><code>
-nanoseconds(long long=0);
-</code></pre>
+<pre><code>microseconds(long long us=0);</code></pre>
 
 <blockquote>
 <dl>
 <dt>Effects:</dt>
 <dd>
-Constructs an object with a count of nanoseconds - default
-is zero.
+Constructs an object of type <code>microseconds</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
+<dt>Postcondition:</dt>
+<dd><code>count() == us;</code></dd>
 </dl>
 </blockquote>
 
-<pre><code>
-nanoseconds(const nanoseconds& rhs);
-</code></pre>
+<pre><code>operator nanoseconds() const;</code></pre>
 
 <blockquote>
 <dl>
-<dt>Effects:</dt>
+<dt>Returns:</dt>
 <dd>
-Copy construction.
+<code>count() * 1000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
+  <h3>
+    <a name="time.milliseconds">32.4 Class milliseconds [time.milliseconds]</a>
+  </h3>
+
+<p>
+Objects of class <code>milliseconds</code> can be used to represent a count of milliseconds. 
+Class <code>milliseconds</code> shall be a duration type ([time.duration.requirements]). 
+For the sake of exposition, the semantics of member functions are not described 
+if they have the same apparent semantics as specified for duration types.</p>
+
+<blockquote>
 <pre><code>
-static tick_type ticks_per_second();
-</code></pre>
+class milliseconds
+{
+public:
+    // <em>traits information</em>
+    typedef <var><strong>implementation-defined</strong></var> tick_type;
+    static const tick_type ticks_per_second = 1000;
+    static const tick_type seconds_per_tick = 0;
+    static const bool is_subsecond = true;
+
+    // <i>construct/copy/destroy functions</i>
+    milliseconds(long long ms=0);
+    milliseconds(milliseconds&&);
+    milliseconds& operator=(milliseconds&&);
+
+    // <em>observer functions</em>
+    tick_type count() const;
+
+<i>    // modifier functions</i>
+    template<typename RhsDuration>
+        milliseconds& operator-=(const RhsDuration& d);
+    template<typename RhsDuration>
+        milliseconds& operator+=(const RhsDuration& d);
+    milliseconds& operator*=(long multiplier);
+    milliseconds& operator/=(long divisor);
+
+    // <i>operations</i>
+    milliseconds operator-() const;
+
+    // <em>conversions</em>
+    operator nanoseconds() const;
+    operator microseconds() const;
+};</code></pre>
+</blockquote>
+
+<pre><code>
+milliseconds(long long ms=0);</code></pre>
 
 <blockquote>
 <dl>
-<dt>Returns:</dt>
+<dt>Effects:</dt>
 <dd>
-1000000000
+Constructs an object of type <code>milliseconds</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
+<dt>Postcondition:</dt>
+<dd><code>count() == ms;</code></dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
+<pre><code>operator nanoseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-0
+<code>count() * 1000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static bool is_subsecond();
-</code></pre>
+<pre><code>operator microseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-true
+<code>count() * 1000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<h3><a name="time.microseconds">31.5 Class microseconds [time.microseconds]</a></h3>
+  <h3>
+    <a name="time.seconds">32.5 Class seconds [time.seconds]</a>
+  </h3>
 
 <p>
-Objects of class <code>microseconds</code>
-can be used to represent a count of microseconds.
-</p>
+Objects of class <code>seconds</code> can be used to represent a count of seconds. 
+Class <code>seconds</code> shall be a duration type ([time.duration.requirements]). 
+For the sake of exposition, the semantics of member functions are not described 
+if they have the same apparent semantics as specified for duration types.</p>
 
 <blockquote>
 <pre><code>
-class microseconds
+class seconds
 {
 public:
-
-    microseconds(long long=0);
-    microseconds(const microseconds& rhs);
-    ~microseconds();
-
-    // <em>conversions</em>
-    operator nanoseconds() const
-
     // <em>traits information</em>
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
     typedef <var><strong>implementation-defined</strong></var> tick_type;
+    static const tick_type ticks_per_second = 1;
+    static const tick_type seconds_per_tick = 1;
+    static const bool is_subsecond = false;
 
-    // <em>+ common functions</em>
-
-};
+    // <i>construct/copy/destroy functions</i>
+    seconds(long long s=0);
+    seconds(seconds&&);
+    seconds& operator=(seconds&&);
 
-</code></pre>
-</blockquote>
+    // <em>observer functions</em>
+    tick_type count() const;
 
-<pre><code>
-microseconds(long long=0);
-</code></pre>
+<i>    // modifier functions</i>
+    template<typename RhsDuration>
+        seconds& operator-=(const RhsDuration& d);
+    template<typename RhsDuration>
+        seconds& operator+=(const RhsDuration& d);
+    seconds& operator*=(long multiplier);
+    seconds& operator/=(long divisor);
 
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Constructs an object with a count of microseconds - default
-is zero.
-</dd>
+    // <i>operations</i>
+    seconds operator-() const;
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
+    // <em>conversions</em>
+    operator nanoseconds() const;
+    operator microseconds() const;
+    operator milliseconds() const;
+};</code></pre>
 </blockquote>
 
 <pre><code>
-microseconds(const microseconds& rhs);
-</code></pre>
+seconds(long long s=0);</code></pre>
 
 <blockquote>
 <dl>
 <dt>Effects:</dt>
 <dd>
-Copy construction.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-// <em>conversions</em>
-operator nanoseconds() const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-microsecond count converted to nanoseconds
+Constructs an object of type <code>seconds</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
+<dt>Postcondition:</dt>
+<dd><code>count() ==  s;</code></dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type ticks_per_second();
-</code></pre>
+<pre><code>operator nanoseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-1000000
+<code>count() * 1000000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
+<pre><code>operator microseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-0
+<code>count() * 1000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static bool is_subsecond();
-</code></pre>
+<pre><code>operator milliseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-true
+<code>count() * 1000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<h3><a name="time.milliseconds">31.6 Class milliseconds [time.milliseconds]</a></h3>
+  <h3>
+    <a name="time.minutes">32.6 Class minutes [time.minutes]</a>
+  </h3>
 
 <p>
-Objects of class <code>milliseconds</code>
-can be used to represent a count of milliseconds.
-</p>
+Objects of class <code>minutes</code> can be used to represent a count of minutes. 
+Class <code>minutes</code> shall be a duration type ([time.duration.requirements]). 
+For the sake of exposition, the semantics of member functions are not described 
+if they have the same apparent semantics as specified for duration types.</p>
 
 <blockquote>
 <pre><code>
-class milliseconds
+class minutes
 {
 public:
-    milliseconds(long long=0);
-    milliseconds(const milliseconds& rhs);
-    ~milliseconds();
-
-    // <em>conversions</em>
-    operator nanoseconds() const;
-    operator microseconds() const;
-
     // <em>traits information</em>
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
     typedef <var><strong>implementation-defined</strong></var> tick_type;
+    static const tick_type ticks_per_second = 0;
+    static const tick_type seconds_per_tick = 60;
+    static const bool is_subsecond = false;
+
+    // <i>construct/copy/destroy functions</i>
+    minutes(long long m=0);
+    minutes(minutes&&);
+    minutes& operator=(minutes&&);
 
-    // <em>+ common functions</em>
-};
-</code></pre>
-</blockquote>
+    // <em>observer functions</em>
+    tick_type count() const;
 
-<pre><code>
-milliseconds(long long=0);
-</code></pre>
+<i>    // modifier functions</i>
+    template<typename RhsDuration>
+        minutes& operator-=(const RhsDuration& d);
+    template<typename RhsDuration>
+        minutes& operator+=(const RhsDuration& d);
+    minutes& operator*=(long multiplier);
+    minutes& operator/=(long divisor);
 
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Constructs an object with a count of milliseconds - default
-is zero.
-</dd>
+    // <i>operations</i>
+    minutes operator-() const;
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
+    // <em>conversions</em>
+    operator nanoseconds() const;
+    operator microseconds() const;
+    operator milliseconds() const;
+    operator seconds() const;
+};</code></pre>
 </blockquote>
 
 <pre><code>
-milliseconds(const milliseconds& rhs);
-</code></pre>
+minutes(long long m=0);</code></pre>
 
 <blockquote>
 <dl>
 <dt>Effects:</dt>
 <dd>
-Copy construction.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-operator nanoseconds() const
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Returns:</dt>
-<dd>
-millisecond count converted to nanoseconds
+Constructs an object of type <code>minutes</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
+<dt>Postcondition:</dt>
+<dd><code>count() == n;</code></dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator microseconds() const
-</code></pre>
+<pre><code>operator nanoseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-millisecond count converted to microseconds
+<code>count() * 60000000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type ticks_per_second();
-</code></pre>
+<pre><code>operator microseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-1000
+<code>count() * 60000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
+<pre><code>operator milliseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-0
+<code>count() * 60000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static bool is_subsecond();
-</code></pre>
+<pre><code>operator seconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-true
+<code>count() * 60</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<h3><a name="time.seconds">31.7 Class seconds [time.seconds]</a></h3>
+  <h3>
+    <a name="time.hours">31.7 Class hours [time.hours]</a>
+  </h3>
 
 <p>
-Objects of class <code>seconds</code>
-can be used to represent a count of seconds.
-</p>
+Objects of class <code>hours</code> can be used to represent a count of hours. 
+Class <code>hours</code> shall be a duration type ([time.duration.requirements]). 
+For the sake of exposition, the semantics of member functions are not described 
+if they have the same apparent semantics as specified for duration types.</p>
 
 <blockquote>
 <pre><code>
-class  seconds
+class hours
 {
 public:
-    seconds(long long s=0);
-    seconds(const seconds& rhs);
-    ~seconds();
-
-    // <em>conversions</em>
-    operator nanoseconds() const
-    operator microseconds() const
-    operator milliseconds() const
-
     // <em>traits information</em>
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
     typedef <var><strong>implementation-defined</strong></var> tick_type;
+    static const tick_type ticks_per_second = 0;
+    static const tick_type seconds_per_tick = 3600;
+    static const bool is_subsecond = false;
+
+    // <i>construct/copy/destroy functions</i>
+    hours(long long h=0);
+    hours(hours&&);
+    hours& operator=(hours&&);
 
-    // <em>+ common functions</em>
-
-};
-</code></pre>
-</blockquote>
-
-<pre><code>
-seconds(long long=0);
-</code></pre>
-
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Construct<var>s</var> an object with a count of seconds - default is
-zero.
-</dd>
-
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
-</blockquote>
-
-<pre><code>
-seconds(const seconds& rhs);
-</code></pre>
+    // <em>observer functions</em>
+    tick_type count() const;
 
-<blockquote>
-<dl>
-<dt>Effects:</dt>
-<dd>
-Copy construction.
-</dd>
+<i>    // modifier functions</i>
+    template<typename RhsDuration>
+        hours& operator-=(const RhsDuration& d);
+    template<typename RhsDuration>
+        hours& operator+=(const RhsDuration& d);
+    hours& operator*=(long multiplier);
+    hours& operator/=(long divisor);
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
-</dl>
+    // <i>operations</i>
+    hours operator-() const;
+
+    // <em>conversions</em>
+    operator nanoseconds() const;
+    operator microseconds() const;
+    operator milliseconds() const;
+    operator seconds() const;
+    operator minutes() const;
+};</code></pre>
 </blockquote>
 
 <pre><code>
-operator nanoseconds() const
-</code></pre>
+hours(long long h=0);</code></pre>
 
 <blockquote>
 <dl>
-<dt>Returns:</dt>
+<dt>Effects:</dt>
 <dd>
-second count converted to nanoseconds
+Constructs an object of type <code>hours</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
+<dt>Postcondition:</dt>
+<dd><code>count() == h;</code></dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator microseconds() const
-</code></pre>
+<pre><code>operator nanoseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-second count converted to microseconds
+<code>count() * 3600000000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator milliseconds() const
-</code></pre>
+<pre><code>operator microseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-second count converted to milliseconds
+<code>count() * 3600000000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type ticks_per_second();
-</code></pre>
+<pre><code>operator milliseconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-1
+<code>count() * 3600000</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
+<pre><code>operator seconds() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-1
+<code>count() * 3600</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static bool is_subsecond();
-</code></pre>
+<pre><code>operator minutes() const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-false
+<code>count() * 60</code>. 
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<h3><a name="time.minutes">31.8 Class minutes [time.minutes]</a></h3>
+  <h3>
+    <a name="time.system">31.8 Class system_time [time.system]</a>
+  </h3>
 
-<p>
-Objects of class <code>minutes</code>
-can be used to represent a count of minutes.
-</p>
+  <p>
+    The class <code>system_time</code> provides a time point
+    that represents the current
+    Coordinated Universal Time, known as UTC, time.
+    <code>system_time</code>
+    shall provide an epoch time of 1970-01-01 00:00:00.000000000
+    and a maximum time value of at least epoch time + 292 years.
+    [<i>Note:</i>
+    292 years represents the number of nanoseconds
+    that can be represented in a signed 64 bit integer.
+    —<i>end note</i>]
+  </p>
 
-<blockquote>
-<pre><code>
-class  minutes
+  <blockquote>
+    <pre><code>class system_time
 {
 public:
-    minutes(long long s=0);
-    minutes(const minutes& rhs);
-    ~minutes();
 
-    // <em>conversions</em>
-    operator nanoseconds() const
-    operator microseconds() const
-    operator milliseconds() const
-    operator seconds() const
+        system_time();
+        explicit system_time(time_t, nanoseconds ns=0);
 
-    // <em>traits information</em>
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
-    typedef <var><strong>implementation-defined</strong></var> tick_type;
+        time_t seconds_since_epoch() const;
+        nanoseconds nanoseconds_since_epoch() const;
 
-    // <em>+ common functions</em>
+        // <em>traits</em>
+        typedef <b><i>implementation defined</i></b> tick_type;
+        static const tick_type ticks_per_second = 1000000000;
+        static const tick_type seconds_per_tick = 0;
+        static const bool is_subsecond = true;
 
-};
-</code></pre>
-</blockquote>
+        // <em>comparison functions</em>
+        bool operator==(const system_time& rhs) const;
+        bool operator!=(const system_time& rhs) const;
+        bool operator>(const system_time& rhs) const;
+        bool operator>=(const system_time& rhs) const;
+        bool operator<(const system_time& rhs) const;
+        bool operator<=(const system_time& rhs) const;
 
-<pre><code>
-minutes(long long=0);
-</code></pre>
+        // <em>arithmetic functions</em>
+        nanoseconds operator-(const system_time& rhs) const
+
+        template<typename Duration>
+        system_time operator+(const Duration& td) const;
+
+        template<typename Duration>
+        system_time& operator+=(const Duration& td);
+
+        template<typename Duration>
+        system_time operator-(const Duration& td) const;
+
+        template<typename Duration>
+        system_time& operator-=(const Duration& td)
+};</code>    </pre>
+  </blockquote>
+
+  <pre><code>system_time();   </code>  </pre>
+
+  <blockquote>
+    <dl>
+      <dt>Effects:</dt>
+      <dd>
+        Constructs a <code>system_time</code>
+        object representing the epoch time point 1970-01-01 00:00:00.000000000
+      </dd>
+
+    </dl>
+  </blockquote>
+
+  <pre><code>system_time(time_t secs, nanoseconds ns=0);</code>  </pre>
+
+  <blockquote>
+    <dl>
+      <dt>Effects:</dt>
+      <dd>
+        Construct<var>s</var> a <code>system_time</code>
+        time object representing the time point
+        <i><code>secs</code></i> + 1,000,000,000*<i><code>ns</code></i> after the epoch.
+      </dd>
+
+      <dt>Remarks:</dt>
+      <dd>
+        If the total nanoseconds is greater than 1 second, the seconds are
+        incremented appropriately.
+      </dd>
+
+    </dl>
+  </blockquote>
+
+  <pre><code>time_t seconds_since_epoch() const;</code>  </pre>
+
+  <blockquote>
+    <dl>
+      <dt>Returns:</dt>
+      <dd>
+        The  seconds since 1970-01-01 00:00:00 represented by the current value 
+        of <code>*this</code>.
+      </dd>
+
+    </dl>
+  </blockquote>
+
+  <pre><code>nanoseconds nanoseconds_since_epoch() const; </code></pre>
 
 <blockquote>
 <dl>
-<dt>Effects:</dt>
+<dt>Returns:</dt>
 <dd>
-Construct<var>s</var> an object with a count of minutes - default is
-zero.
+The  nanoseconds
+since 1970-01-01 00:00:00 represented by the current value of <code>*this</code>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-minutes(const minutes& rhs);
-</code></pre>
+<pre><code>bool operator==(const system_time& rhs) const;</code></pre>
 
 <blockquote>
 <dl>
-<dt>Effects:</dt>
+<dt>Returns:</dt>
 <dd>
-Copy construction.
+True if
+the time point
+represented by <code>*this</code> is the same as the time point represented by <var>
+<code>rhs</code></var>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator nanoseconds() const
-</code></pre>
+<pre><code>bool operator!=(const system_time& rhs) const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-minute count converted to nanoseconds
+True if the time point represented by <code>*this</code> is not the same as the time 
+point represented
+by <var><code>rhs</code></var>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator microseconds() const
-</code></pre>
+<pre><code>bool operator>(const system_time& rhs) const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-minute count converted to microseconds
+True if the time point represented by
+<code>*this</code> is later than the time point represented by <var><code>rhs</code></var>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator milliseconds() const
-</code></pre>
+<pre><code>bool operator>=(const system_time& rhs) const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-minute count converted to milliseconds
+True if the time point represented
+by <code>*this</code> is later or the same as the time point represented by <var>
+<code>rhs</code></var>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator seconds() const
-</code></pre>
+<pre><code>bool operator<(const system_time& rhs) const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-minute count converted to seconds
+True if the time point represented by <code>*this</code>
+is earlier than the time point represented by <var><code>rhs</code></var>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type ticks_per_second();
-</code></pre>
+<pre><code>bool operator<=(const system_time& rhs) const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-0
+True if the time  pointrepresented by <code>*this</code>
+is earlier or the same as the time point represented by <var><code>rhs</code></var>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type seconds_per_tick();
-</code></pre>
+<pre><code>nanoseconds operator-(const system_time& <var>rhs</var>) const</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-60
+The difference in nanoseconds between
+the time point represented by <code>*this</code> and
+the time point represented by <code><var>rhs</var></code>.
 </dd>
 
-<dt>Throws:</dt>
+<dt>Remarks:</dt>
 <dd>
-Nothing.
+If <code>*this < rhs</code>, the result will be negative.
 </dd>
+
 </dl>
 </blockquote>
 
-<pre><code>
-static bool is_subsecond();
-</code></pre>
+<pre><code>template<typename Duration>
+  system_time operator+(const Duration& td) const;</code></pre>
 
 <blockquote>
 <dl>
 <dt>Returns:</dt>
 <dd>
-false
+The sum of <code>td</code> converted to nanosecond resolution
+and the time represented by <code>*this</code>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<h3><a name="time.hours">31.9 Class hours [time.hours]</a></h3>
-
-<p>
-Objects of class <code>hours</code>
-can be used to represent a count of hours.
-</p>
+<pre><code>template<typename Duration>
+  system_time& operator+=(const Duration& td);</code></pre>
 
 <blockquote>
-<pre><code>
-class  hours
-{
-public:
-    hours(long long s=0);
-    hours(const hours& rhs);
-    ~hours();
-
-    // <em>conversions</em>
-    operator nanoseconds() const
-    operator microseconds() const
-    operator milliseconds() const
-    operator seconds() const
-    operator minutes() const
-
-    // <em>traits information</em>
-    static tick_type ticks_per_second();
-    static tick_type seconds_per_tick();
-    static bool is_subsecond();
-    typedef <var><strong>implementation-defined</strong></var> tick_type;
+<dl>
+<dt>Effects:</dt>
+<dd>
+Converts <code>td</code> to nanosecond resolution
+and adds it to the time represented by <code>*this</code>.
+</dd>
 
-    // <em>+ common functions</em>
+<dt>Returns:</dt>
+<dd>
+<code>*this</code></dd>
 
-};
-</code></pre>
+</dl>
 </blockquote>
 
-<pre><code>
-hours(long long=0);
-</code></pre>
+<pre><code>template<typename Duration>
+  system_time operator-(const Duration& td) const;</code></pre>
 
 <blockquote>
 <dl>
-<dt>Effects:</dt>
+<dt>Returns:</dt>
 <dd>
-Construct<var>s</var> an object with a count of hours - default is zero.
+The difference between the time represented by <code>*this</code> converted to nanosecond resolution
+and  <code>td</code>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-hours(const hours& rhs);
-</code></pre>
+<pre><code>template<typename Duration>
+  system_time& operator-=(const Duration& td)</code></pre>
 
 <blockquote>
 <dl>
 <dt>Effects:</dt>
 <dd>
-Copy construction.
+Converts <code>td</code> to nanosecond resolution
+and subtracts it from the time represented by <code>*this</code>.
 </dd>
 
-<dt>Throws:</dt>
+<dt>Returns:</dt>
 <dd>
-Nothing.
-</dd>
+<code>*this</code></dd>
+
 </dl>
 </blockquote>
 
-<pre><code>
-operator nanoseconds() const
-</code></pre>
+
+<h3><a name="time.nonmembers">32.9 Non-member functions[time.nonmembers]</a></h3>
+
+<pre><code>system_time get_system_time();</code></pre>
 
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-hour count converted to nanoseconds
-</dd>
-
-<dt>Throws:</dt>
+The system time as provided by the operating system.</dd>
 <dd>
-Nothing.
-</dd>
+ </dd>
+<dd>
+<i> [Note:</i> Provides access to the system clock at a
+resolution as fine as nanoseconds.
+The actual resolution may vary.<i> --end note]</i></dd>
+<dt> </dt>
+  <dt>[Note: <span style="font-style: normal">No error reporting is provided. 
+  Hosted implementations ([intro.compliance]) presumably utilize system clock 
+  API's that never report errors. </span>--end note.] </dt>
+
 </dl>
 </blockquote>
 
-<pre><code>
-operator microseconds() const
-</code></pre>
 
+<pre><code>template<typename Duration>
+  system_time operator+(const Duration& td, const system_time& rhs);</code></pre>
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-hour count converted to microseconds
-</dd>
+The sum of <code>td</code> converted to nanosecond resolution
+and the time represented by <code>rhs</code>. </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-operator milliseconds() const
-</code></pre>
 
+<pre><code>template <class LhsDuration, class RhsDuration>
+  bool operator==(const LhsDuration& lhs, const RhsDuration& rhs);</code></pre>
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-hour count converted to milliseconds
-</dd>
+If the resolution of <code>LhsDuration</code> is the same as the resolution of
+<code>RhsDuration</code>, <code>lhs.count()==rhs.count()</code>. 
+Otherwise, if the resolution of <code>LhsDuration</code> is finer than the 
+resolution of <code>RhsDuration</code>, <code>lhs.count()==x, where x is 
+rhs.count() </code>converted to the resolution of <code>LhsDuration</code>. 
+Otherwise,  <code>x==rhs.count(), where x is lhs.count() </code>
+converted to the resolution of <code>RhsDuration</code>.</dd>
 
-<dt>Throws:</dt>
+</dl>
+</blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  bool operator!=(const LhsDuration& lhs, const RhsDuration& rhs);</code></pre>
+<blockquote>
+<dl>
+
+<dt>Returns:</dt>
 <dd>
-Nothing.
-</dd>
+<code>!(lhs==rhs)</code>.</dd>
+
 </dl>
 </blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  bool operator< (const LhsDuration& lhs, const RhsDuration& rhs);</code></pre>
+<blockquote>
+<dl>
 
-<pre><code>
-operator seconds() const
-</code></pre>
+<dt>Returns:</dt>
+<dd>
+If the resolution of <code>LhsDuration</code> is the same as the resolution of
+<code>RhsDuration</code>, <code>lhs.count()<rhs.count()</code>. 
+Otherwise, if the resolution of <code>LhsDuration</code> is finer than the 
+resolution of <code>RhsDuration</code>, <code>lhs.count()<x, where x is 
+rhs.count() </code>converted to the resolution of <code>LhsDuration</code>. 
+Otherwise,  <code>x<rhs.count(), where x is lhs.count() </code>
+converted to the resolution of <code>RhsDuration</code>.</dd>
 
+</dl>
+</blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  bool operator<=(const LhsDuration& lhs, const RhsDuration& rhs);</code></pre>
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-hour count converted to seconds
-</dd>
+<code>!(rhs<lhs)</code>.</dd>
 
-<dt>Throws:</dt>
+</dl>
+</blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  bool operator> (const LhsDuration& lhs, const RhsDuration& rhs);</code></pre>
+<blockquote>
+<dl>
+
+<dt>Returns:</dt>
 <dd>
-Nothing.
-</dd>
+<code>rhs<lhs)</code>.</dd>
+
 </dl>
 </blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  bool operator>=(const LhsDuration& lhs, const RhsDuration& rhs);</code></pre>
+<blockquote>
+<dl>
 
-<pre><code>
-operator minutes() const
-</code></pre>
+<dt>Returns:</dt>
+<dd>
+<code>!(lhs<rhs)</code>.</dd>
 
+</dl>
+</blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  <i>FRDuration</i> operator+(const LhsDuration& lhs, const RhsDuration& rhs)</code></pre>
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-hour count converted to seconds.
-</dd>
+If the resolution of <code>LhsDuration</code> is the same as the resolution of
+<code>RhsDuration</code>, <code>LhsDuration(lhs.count()+rhs.count())</code>. 
+Otherwise, if the resolution of <code>LhsDuration</code> is finer than the 
+resolution of <code>RhsDuration</code>, <code>LhsDuration(lhs.count()+x), 
+where x is rhs.count() </code>converted to the resolution of <code>
+LhsDuration</code>. Otherwise,  <code>RhsDuration(x+rhs.count()), where 
+x is lhs.count() </code>converted to the resolution of <code>RhsDuration</code>.</dd>
 
-<dt>Throws:</dt>
+</dl>
+</blockquote>
+<pre><code>template <class LhsDuration, class RhsDuration>
+  <i>FRDuration</i> operator-(const LhsDuration& lhs, const RhsDuration& rhs)</code></pre>
+<blockquote>
+<dl>
+
+<dt>Returns:</dt>
 <dd>
-Nothing.
-</dd>
+If the resolution of <code>LhsDuration</code> is the same as the resolution of
+<code>RhsDuration</code>, <code>LhsDuration(lhs.count()-rhs.count())</code>. 
+Otherwise, if the resolution of <code>LhsDuration</code> is finer than the 
+resolution of <code>RhsDuration</code>, <code>LhsDuration(lhs.count()-x), 
+where x is rhs.count() </code>converted to the resolution of <code>
+LhsDuration</code>. Otherwise,  <code>RhsDuration(x-rhs.count()), where 
+x is lhs.count() </code>converted to the resolution of <code>RhsDuration</code>.</dd>
+
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type ticks_per_second();
+<pre><code>template <class Duration>
+  Duration operator*(Duration lhs, long rhs)
 </code></pre>
-
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-0
+<code>lhs *= rhs</code>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static tick_type seconds_per_tick();
+<pre><code>template <class Duration>
+  Duration operator*(long lhs, Duration rhs)
 </code></pre>
-
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-3600
+<code>rhs *= lhs</code>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>
 
-<pre><code>
-static bool is_subsecond();
+<pre><code>template <class Duration>
+  Duration operator/(Duration lhs, long rhs)
 </code></pre>
-
 <blockquote>
 <dl>
+
 <dt>Returns:</dt>
 <dd>
-false
+<code>lhs /= rhs</code>.
 </dd>
 
-<dt>Throws:</dt>
-<dd>
-Nothing.
-</dd>
 </dl>
 </blockquote>