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| <div class="section"> |
| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="phoenix.primitives"></a><a class="link" href="primitives.html" title="Primitives">Primitives</a> |
| </h2></div></div></div> |
| <div class="toc"><dl> |
| <dt><span class="section"><a href="primitives.html#phoenix.primitives.arguments">Arguments</a></span></dt> |
| <dt><span class="section"><a href="primitives.html#phoenix.primitives.values">Values</a></span></dt> |
| <dt><span class="section"><a href="primitives.html#phoenix.primitives.references">References</a></span></dt> |
| <dt><span class="section"><a href="primitives.html#phoenix.primitives.constant_references">Constant References</a></span></dt> |
| <dt><span class="section"><a href="primitives.html#phoenix.primitives.nothing">Nothing</a></span></dt> |
| </dl></div> |
| <p> |
| Actors are composed to create more complex actors in a tree-like hierarchy. |
| The primitives are atomic entities that are like the leaves in the tree. Phoenix |
| is extensible. New primitives can be added anytime. Right out of the box, there |
| are only a few primitives. This section shall deal with these preset primitives. |
| </p> |
| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="phoenix.primitives.arguments"></a><a class="link" href="primitives.html#phoenix.primitives.arguments" title="Arguments">Arguments</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">home</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">argument</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| We use an instance of: |
| </p> |
| <pre class="programlisting"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="identifier">N</span><span class="special">></span> <span class="special">></span> |
| </pre> |
| <p> |
| to represent the Nth function argument. The argument placeholder acts as |
| an imaginary data-bin where a function argument will be placed. |
| </p> |
| <a name="phoenix.primitives.arguments.predefined_arguments"></a><h3> |
| <a name="id837325"></a> |
| <a class="link" href="primitives.html#phoenix.primitives.arguments.predefined_arguments">Predefined |
| Arguments</a> |
| </h3> |
| <p> |
| There are a few predefined instances of <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="identifier">N</span><span class="special">></span> |
| <span class="special">></span></code> named <code class="computeroutput"><span class="identifier">arg1</span></code>..<code class="computeroutput"><span class="identifier">argN</span></code>, and its <a href="http://www.boost.org/libs/lambda/doc/index.html" target="_top">BLL</a> |
| counterpart <code class="computeroutput"><span class="identifier">_1</span></code>..<code class="computeroutput"><span class="identifier">_N</span></code>. (where N is a predefined maximum). |
| </p> |
| <p> |
| Here are some sample preset definitions of <code class="computeroutput"><span class="identifier">arg1</span></code>..<code class="computeroutput"><span class="identifier">argN</span></code> |
| </p> |
| <pre class="programlisting"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">0</span><span class="special">></span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">arg1</span> <span class="special">=</span> <span class="identifier">argument</span><span class="special"><</span><span class="number">0</span><span class="special">>();</span> |
| <span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">1</span><span class="special">></span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">arg2</span> <span class="special">=</span> <span class="identifier">argument</span><span class="special"><</span><span class="number">1</span><span class="special">>();</span> |
| <span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">2</span><span class="special">></span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">arg3</span> <span class="special">=</span> <span class="identifier">argument</span><span class="special"><</span><span class="number">2</span><span class="special">>();</span> |
| </pre> |
| <p> |
| and its <a href="http://www.boost.org/libs/lambda/doc/index.html" target="_top">BLL</a> |
| <code class="computeroutput"><span class="identifier">_1</span></code>..<code class="computeroutput"><span class="identifier">_N</span></code> |
| style counterparts: |
| </p> |
| <pre class="programlisting"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">0</span><span class="special">></span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">_1</span> <span class="special">=</span> <span class="identifier">argument</span><span class="special"><</span><span class="number">0</span><span class="special">>();</span> |
| <span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">1</span><span class="special">></span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">_2</span> <span class="special">=</span> <span class="identifier">argument</span><span class="special"><</span><span class="number">1</span><span class="special">>();</span> |
| <span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">2</span><span class="special">></span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">_3</span> <span class="special">=</span> <span class="identifier">argument</span><span class="special"><</span><span class="number">2</span><span class="special">>();</span> |
| </pre> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| You can set <code class="computeroutput"><span class="identifier">PHOENIX_ARG_LIMIT</span></code>, |
| the predefined maximum placeholder index. By default, <code class="computeroutput"><span class="identifier">PHOENIX_ARG_LIMIT</span></code> |
| is set to <code class="computeroutput"><span class="identifier">PHOENIX_LIMIT</span></code> |
| (See <a class="link" href="actors.html" title="Actors">Actors</a>). |
| </p></td></tr> |
| </table></div> |
| <a name="phoenix.primitives.arguments.user_defined_arguments"></a><h3> |
| <a name="id837833"></a> |
| <a class="link" href="primitives.html#phoenix.primitives.arguments.user_defined_arguments">User |
| Defined Arguments</a> |
| </h3> |
| <p> |
| When appropriate, you can define your own <code class="computeroutput"><span class="identifier">argument</span><span class="special"><</span><span class="identifier">N</span><span class="special">></span></code> |
| names. For example: |
| </p> |
| <pre class="programlisting"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">argument</span><span class="special"><</span><span class="number">0</span><span class="special">></span> <span class="special">></span> <span class="identifier">x</span><span class="special">;</span> <span class="comment">// note zero based index |
| </span></pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">x</span></code> may now be used as a parameter |
| to a lazy function: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> <span class="number">6</span><span class="special">)</span> |
| </pre> |
| <p> |
| which is equivalent to: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="number">6</span><span class="special">)</span> |
| </pre> |
| <a name="phoenix.primitives.arguments.evaluating_an_argument"></a><h3> |
| <a name="id837980"></a> |
| <a class="link" href="primitives.html#phoenix.primitives.arguments.evaluating_an_argument">Evaluating |
| an Argument</a> |
| </h3> |
| <p> |
| An argument, when evaluated, selects the Nth argument from the those passed |
| in by the client. |
| </p> |
| <p> |
| For example: |
| </p> |
| <pre class="programlisting"><span class="keyword">char</span> <span class="identifier">c</span> <span class="special">=</span> <span class="char">'A'</span><span class="special">;</span> |
| <span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">123</span><span class="special">;</span> |
| <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">s</span> <span class="special">=</span> <span class="string">"Hello World"</span><span class="special">;</span> |
| |
| <span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">arg1</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> <span class="comment">// Get the 1st argument: c |
| </span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">arg1</span><span class="special">(</span><span class="identifier">i</span><span class="special">,</span> <span class="identifier">s</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> <span class="comment">// Get the 1st argument: i |
| </span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">arg2</span><span class="special">(</span><span class="identifier">i</span><span class="special">,</span> <span class="identifier">s</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span> <span class="comment">// Get the 2nd argument: s |
| </span></pre> |
| <p> |
| will print out: |
| </p> |
| <pre class="programlisting"><span class="identifier">A</span> |
| <span class="number">123</span> |
| <span class="identifier">Hello</span> <span class="identifier">World</span> |
| </pre> |
| <a name="phoenix.primitives.arguments.extra_arguments"></a><h3> |
| <a name="id838250"></a> |
| <a class="link" href="primitives.html#phoenix.primitives.arguments.extra_arguments">Extra Arguments</a> |
| </h3> |
| <p> |
| In C and C++, a function can have extra arguments that are not at all used |
| by the function body itself. These extra arguments are simply ignored. |
| </p> |
| <p> |
| Phoenix also allows extra arguments to be passed. For example, recall our |
| original <code class="computeroutput"><span class="identifier">add</span></code> function: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">arg2</span><span class="special">)</span> |
| </pre> |
| <p> |
| We know now that partially applying this function results to a function that |
| expects 2 arguments. However, the library is a bit more lenient and allows |
| the caller to supply more arguments than is actually required. Thus, <code class="computeroutput"><span class="identifier">add</span></code> actually allows 2 <span class="emphasis"><em>or more</em></span> |
| arguments. For instance, with: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">arg2</span><span class="special">)(</span><span class="identifier">x</span><span class="special">,</span> <span class="identifier">y</span><span class="special">,</span> <span class="identifier">z</span><span class="special">)</span> |
| </pre> |
| <p> |
| the third argument <code class="computeroutput"><span class="identifier">z</span></code> is ignored. |
| Taking this further, in-between arguments are also ignored. Example: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">arg5</span><span class="special">)(</span><span class="identifier">a</span><span class="special">,</span> <span class="identifier">b</span><span class="special">,</span> <span class="identifier">c</span><span class="special">,</span> <span class="identifier">d</span><span class="special">,</span> <span class="identifier">e</span><span class="special">)</span> |
| </pre> |
| <p> |
| Here, arguments b, c, and d are ignored. The function <code class="computeroutput"><span class="identifier">add</span></code> |
| takes in the first argument (<code class="computeroutput"><span class="identifier">arg1</span></code>) |
| and the fifth argument (<code class="computeroutput"><span class="identifier">arg5</span></code>). |
| </p> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../doc/src/images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| There are a few reasons why enforcing strict arity is not desirable. A |
| case in point is the callback function. Typical callback functions provide |
| more information than is actually needed. Lambda functions are often used |
| as callbacks. |
| </p></td></tr> |
| </table></div> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="phoenix.primitives.values"></a><a class="link" href="primitives.html#phoenix.primitives.values" title="Values">Values</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">home</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">value</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| Whenever we see a constant in a partially applied function, an |
| </p> |
| <pre class="programlisting"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">value</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="special">></span> |
| </pre> |
| <p> |
| (where T is the type of the constant) is automatically created for us. For |
| instance: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="number">6</span><span class="special">)</span> |
| </pre> |
| <p> |
| Passing a second argument, <code class="computeroutput"><span class="number">6</span></code>, |
| an <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">value</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="special">></span></code> |
| is implicitly created behind the scenes. This is also equivalent to: |
| </p> |
| <pre class="programlisting"><span class="identifier">add</span><span class="special">(</span><span class="identifier">arg1</span><span class="special">,</span> <span class="identifier">val</span><span class="special">(</span><span class="number">6</span><span class="special">))</span> |
| </pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">val</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code> generates |
| an <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">value</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="special">></span></code> where <code class="computeroutput"><span class="identifier">T</span></code> |
| is the type of <code class="computeroutput"><span class="identifier">x</span></code>. In most |
| cases, there's no need to explicitly use <code class="computeroutput"><span class="identifier">val</span></code>, |
| but, as we'll see later on, there are situations where this is unavoidable. |
| </p> |
| <a name="phoenix.primitives.values.evaluating_a_value"></a><h3> |
| <a name="id838775"></a> |
| <a class="link" href="primitives.html#phoenix.primitives.values.evaluating_a_value">Evaluating a |
| Value</a> |
| </h3> |
| <p> |
| Like arguments, values are also actors. As such, values can be evaluated. |
| Invoking a value gives the value's identity. Example: |
| </p> |
| <pre class="programlisting"><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">val</span><span class="special">(</span><span class="number">3</span><span class="special">)()</span> <span class="special"><<</span> <span class="identifier">val</span><span class="special">(</span><span class="string">"Hello World"</span><span class="special">)();</span> |
| </pre> |
| <p> |
| prints out "3 Hello World". |
| </p> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="phoenix.primitives.references"></a><a class="link" href="primitives.html#phoenix.primitives.references" title="References">References</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">home</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">reference</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| Values are immutable constants. Attempting to modify a value will result |
| in a compile time error. When we want the function to modify the parameter, |
| we use a reference instead. For instance, imagine a lazy function <code class="computeroutput"><span class="identifier">add_assign</span></code>: |
| </p> |
| <pre class="programlisting"><span class="keyword">void</span> <span class="identifier">add_assign</span><span class="special">(</span><span class="identifier">T</span><span class="special">&</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">T</span> <span class="identifier">y</span><span class="special">)</span> <span class="special">{</span> <span class="identifier">x</span> <span class="special">+=</span> <span class="identifier">y</span><span class="special">;</span> <span class="special">}</span> <span class="comment">// pseudo code |
| </span></pre> |
| <p> |
| Here, we want the first function argument, x, to be mutable. Obviously, we |
| cannot write: |
| </p> |
| <pre class="programlisting"><span class="identifier">add_assign</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">2</span><span class="special">)</span> <span class="comment">// error first argument is immutable |
| </span></pre> |
| <p> |
| In C++, we can pass in a reference to a variable as the first argument in |
| our example above. Yet, by default, the library forces arguments passed to |
| partially applied functions functions to be immutable values (see <a class="link" href="primitives.html#phoenix.primitives.values" title="Values">Values</a>). |
| To achieve our intent, we use: |
| </p> |
| <pre class="programlisting"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">reference</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> <span class="special">></span> |
| </pre> |
| <p> |
| This is similar to <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">value</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> |
| <span class="special">></span></code> above but instead holds a reference |
| to a variable. |
| </p> |
| <p> |
| We normally don't instantiate <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">reference</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> |
| <span class="special">></span></code> objects directly. Instead we |
| use <code class="computeroutput"><span class="identifier">ref</span></code>. For example (where |
| <code class="computeroutput"><span class="identifier">i</span></code> is an <code class="computeroutput"><span class="keyword">int</span></code> |
| variable): |
| </p> |
| <pre class="programlisting"><span class="identifier">add_assign</span><span class="special">(</span><span class="identifier">ref</span><span class="special">(</span><span class="identifier">i</span><span class="special">),</span> <span class="number">2</span><span class="special">)</span> |
| </pre> |
| <a name="phoenix.primitives.references.evaluating_a_reference"></a><h3> |
| <a name="id839204"></a> |
| <a class="link" href="primitives.html#phoenix.primitives.references.evaluating_a_reference">Evaluating |
| a Reference</a> |
| </h3> |
| <p> |
| References are actors. Hence, references can be evaluated. Such invocation |
| gives the reference's identity. Example: |
| </p> |
| <pre class="programlisting"><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> |
| <span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">s</span> <span class="special">=</span> <span class="string">"Hello World"</span><span class="special">;</span> |
| <span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">ref</span><span class="special">(</span><span class="identifier">i</span><span class="special">)()</span> <span class="special"><<</span> <span class="identifier">ref</span><span class="special">(</span><span class="identifier">s</span><span class="special">)();</span> |
| </pre> |
| <p> |
| prints out "3 Hello World" |
| </p> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="phoenix.primitives.constant_references"></a><a class="link" href="primitives.html#phoenix.primitives.constant_references" title="Constant References">Constant References</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">home</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">reference</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| Another free function <code class="computeroutput"><span class="identifier">cref</span><span class="special">(</span><span class="identifier">cv</span><span class="special">)</span></code> |
| may also be used. <code class="computeroutput"><span class="identifier">cref</span><span class="special">(</span><span class="identifier">cv</span><span class="special">)</span></code> creates |
| an <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">reference</span><span class="special"><</span><span class="identifier">T</span> <span class="keyword">const</span><span class="special">&></span> <span class="special">></span></code> |
| object. This is similar to <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">value</span><span class="special"><</span><span class="identifier">T</span><span class="special">></span> |
| <span class="special">></span></code> but when the data to be passed |
| as argument to a function is heavy and expensive to copy by value, the <code class="computeroutput"><span class="identifier">cref</span><span class="special">(</span><span class="identifier">cv</span><span class="special">)</span></code> offers a lighter alternative. |
| </p> |
| </div> |
| <div class="section"> |
| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="phoenix.primitives.nothing"></a><a class="link" href="primitives.html#phoenix.primitives.nothing" title="Nothing">Nothing</a> |
| </h3></div></div></div> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">home</span><span class="special">/</span><span class="identifier">phoenix</span><span class="special">/</span><span class="identifier">core</span><span class="special">/</span><span class="identifier">nothing</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| Finally, the <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">null_actor</span><span class="special">></span></code> |
| does nothing; (a "bum", if you will :-). There's a sole <code class="computeroutput"><span class="identifier">actor</span><span class="special"><</span><span class="identifier">null_actor</span><span class="special">></span></code> |
| instance named "nothing". This actor is actually useful in situations |
| where we don't want to do anything. (See <a class="link" href="composite.html#phoenix.composite.statement.for__statement" title="for_ Statement">for_ |
| Statement</a> for example). |
| </p> |
| </div> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2002-2005 Joel |
| de Guzman, Dan Marsden<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
| </p> |
| </div></td> |
| </tr></table> |
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