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various documentation fixes

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Andrzej Krzemienski
2014-06-20 16:25:57 +02:00
parent 4cbb67e505
commit 599c75a6d3
7 changed files with 211 additions and 222 deletions
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doc/html/boost_optional/quick_start.html
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@ -53,7 +53,7 @@
is possible. A natural signature for this function can be:
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">optional</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">optionl</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">convert</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">text</span><span class="special">);</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">convert</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">text</span><span class="special">);</span>
</pre>
<p>
All necessary functionality can be included with one header <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">optional</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>.
@ -65,16 +65,16 @@
can use our function:
</p>
<pre class="programlisting"><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">text</span> <span class="special">=</span> <span class="comment">/*... */</span><span class="special">;</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">optionl</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">oi</span> <span class="special">=</span> <span class="identifier">convert</span><span class="special">(</span><span class="identifier">text</span><span class="special">);</span> <span class="comment">// move-construct</span>
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">oi</span><span class="special">)</span> <span class="comment">// contextual conversion to bool</span>
<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">oi</span><span class="special">;</span> <span class="comment">// operator*</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">oi</span> <span class="special">=</span> <span class="identifier">convert</span><span class="special">(</span><span class="identifier">text</span><span class="special">);</span> <span class="comment">// move-construct</span>
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">oi</span><span class="special">)</span> <span class="comment">// contextual conversion to bool</span>
<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">oi</span><span class="special">;</span> <span class="comment">// operator*</span>
</pre>
<p>
In order to test if <code class="computeroutput"><span class="identifier">optional</span></code>
contains a value, we use the contextual conversion to type <code class="computeroutput"><span class="keyword">bool</span></code>. Because of this we can combine the initialization
of the optional object and the test into one instruction:
</p>
<pre class="programlisting"><span class="keyword">if</span> <span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optionl</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">oi</span> <span class="special">=</span> <span class="identifier">convert</span><span class="special">(</span><span class="identifier">text</span><span class="special">))</span>
<pre class="programlisting"><span class="keyword">if</span> <span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">oi</span> <span class="special">=</span> <span class="identifier">convert</span><span class="special">(</span><span class="identifier">text</span><span class="special">))</span>
<span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">*</span><span class="identifier">oi</span><span class="special">;</span>
</pre>
<p>
@ -114,10 +114,13 @@
Finally, you can provide a callback to be called when trying to access the
contained value fails:
</p>
<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">l</span> <span class="special">=</span> <span class="identifier">convert</span><span class="special">(</span><span class="identifier">text</span><span class="special">).</span><span class="identifier">value_or_eval</span><span class="special">([]()</span> <span class="special">-&gt;</span> <span class="keyword">int</span> <span class="special">{</span>
<span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"could not convert; using -1 instead"</span> <span class="special">&lt;&lt;</span> <span class="identifier">endl</span><span class="special">;</span>
<pre class="programlisting"><span class="keyword">int</span> <span class="identifier">fallback_to_default</span><span class="special">()</span>
<span class="special">{</span>
<span class="identifier">cerr</span> <span class="special">&lt;&lt;</span> <span class="string">"could not convert; using -1 instead"</span> <span class="special">&lt;&lt;</span> <span class="identifier">endl</span><span class="special">;</span>
<span class="keyword">return</span> <span class="special">-</span><span class="number">1</span><span class="special">;</span>
<span class="special">});</span>
<span class="special">}</span>
<span class="keyword">int</span> <span class="identifier">l</span> <span class="special">=</span> <span class="identifier">convert</span><span class="special">(</span><span class="identifier">text</span><span class="special">).</span><span class="identifier">value_or_eval</span><span class="special">(</span><span class="identifier">fallback_to_default</span><span class="special">);</span>
</pre>
<p>
This will call the provided callback and return whatever the callback returns.
@ -128,7 +131,7 @@
Now, let's consider how function <code class="computeroutput"><span class="identifier">convert</span></code>
can be implemented.
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optionl</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">convert</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">text</span><span class="special">)</span>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">convert</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">text</span><span class="special">)</span>
<span class="special">{</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">stringstream</span> <span class="identifier">s</span><span class="special">(</span><span class="identifier">text</span><span class="special">);</span>
<span class="keyword">int</span> <span class="identifier">i</span><span class="special">;</span>