schancel/std_concepts.html

## std_concepts.html
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<h1>std.concepts</h1>
<div id=quickindex class=quickindex></div>
<!-- Generated by Ddoc from std/concepts.d -->
Functions and types that manipulate built-in arrays.
<p></p>
<b>License:</b><br><a href="http://boost.org/LICENSE_1_0.txt">Boost License 1.0</a>.

<p></p>
<b>Authors:</b><br>Shammah Chancellor

<p></p>
<b>Source:</b><br>
<a href="https://github.com/D-Programming-Language/phobos/blob/master/std/concepts.d">std/concepts.d</a><p></p>

<dl><dt class="d_decl"><a name=".isConcept"></a>bool <a name="isConcept"></a><span class="ddoc_psymbol">isConcept</span>(T, C, bool diagnostics = false, string errorPrefix = "")();
</dt>
<dd>Returns <span class="d_inlinecode"><b>true</b></span> if <span class="d_inlinecode">T</span> supports the concept <span class="d_inlinecode">C</span>.   Note, templated member functions are not supported currently.
<p></p>
Concepts should be defined as in the following example:
<pre class="d_code"><span class="d_keyword">class</span> CInputRange(E) : Concept
{
	<span class="d_keyword">abstract</span> <span class="d_keyword">void</span> popFront();
	@property <span class="d_keyword">abstract</span> E front();
	<span class="d_keyword">bool</span> empty;

	<span class="d_comment">//Optional Axioms function.  This will be checked if it compiles, and that it returns true if it does.
</span>	<span class="d_keyword">static</span> <span class="d_keyword">bool</span> Axioms(T)()
	{
		<span class="d_keyword">return</span> <span class="d_keyword">true</span>;
	}
}

<span class="d_keyword">class</span> CInfinite() : Concept
{
	<span class="d_keyword">static</span> <span class="d_keyword">bool</span> Axioms(T)() {
		<span class="d_keyword">enum</span> empty = T.empty;
		<span class="d_keyword">return</span> !empty;
	}
}

<span class="d_keyword">class</span> CInfiniteInputRange(E) : CInputRange!E
{
	<span class="d_keyword">mixin</span> CInfinite;
}
</pre>
<p></p>

</dd>
<dt class="d_decl"><a name=".conceptDiagnostic"></a>template <a name="conceptDiagnostic"></a><span class="ddoc_psymbol">conceptDiagnostic</span>(R, string F, int L, C...)</dt>
<dd>Prints error messages for why template instantiation failed.
<p></p>
<b>Examples:</b><br><pre class="d_code"><span class="d_keyword">bool</span> DoStuff(R)(R infRange) <span class="d_keyword">if</span> ( isConcept!(R, CInfiniteInputRange!string))
{
	<span class="d_keyword">return</span> <span class="d_keyword">true</span>;
}

<span class="d_keyword">bool</span> DoStuff(R)(R infRange) <span class="d_keyword">if</span> ( isConcept!(R, COutputRange!string))
{
	<span class="d_keyword">return</span> <span class="d_keyword">true</span>;
}

<span class="d_comment">//Example of using conceptDiagnostic
</span><span class="d_keyword">bool</span> DoStuff(R, string F = <span class="d_keyword">__FILE__</span>, size_t L = <span class="d_keyword">__LINE__</span> )(R infRange)
{
	<span class="d_keyword">mixin</span> <span class="d_psymbol">conceptDiagnostic</span>!(R, F, L, COutputRange!string, CInfiniteInputRange!string);
	<span class="d_keyword">return</span> <span class="d_keyword">false</span>;
}
</pre>
<p></p>

</dd>
<dt class="d_decl"><a name=".Concept"></a>class <a name="Concept"></a><span class="ddoc_psymbol">Concept</span>;
</dt>
<dd>Base class for Concepts.  All Concepts should derive from this, or another concept.<p></p>

</dd>
</dl>

</div><!--/content-->


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	<h1>std.concepts</h1>
	<div id=quickindex class=quickindex></div>
	<!-- Generated by Ddoc from std/concepts.d -->
	Functions and types that manipulate built-in arrays.
	<p></p>
	<b>License:</b><br><a href="http://boost.org/LICENSE_1_0.txt">Boost License 1.0</a>.

	<p></p>
	<b>Authors:</b><br>Shammah Chancellor

	<p></p>
	<b>Source:</b><br>
	<a href="https://github.com/D-Programming-Language/phobos/blob/master/std/concepts.d">std/concepts.d</a><p></p>

	<dl><dt class="d_decl"><a name=".isConcept"></a>bool <a name="isConcept"></a><span class="ddoc_psymbol">isConcept</span>(T, C, bool diagnostics = false, string errorPrefix = "")();
	</dt>
	<dd>Returns <span class="d_inlinecode"><b>true</b></span> if <span class="d_inlinecode">T</span> supports the concept <span class="d_inlinecode">C</span>. Note, templated member functions are not supported currently.
	<p></p>
	Concepts should be defined as in the following example:
	<pre class="d_code"><span class="d_keyword">class</span> CInputRange(E) : Concept
	{
	<span class="d_keyword">abstract</span> <span class="d_keyword">void</span> popFront();
	@property <span class="d_keyword">abstract</span> E front();
	<span class="d_keyword">bool</span> empty;

	<span class="d_comment">//Optional Axioms function. This will be checked if it compiles, and that it returns true if it does.
	</span> <span class="d_keyword">static</span> <span class="d_keyword">bool</span> Axioms(T)()
	{
	<span class="d_keyword">return</span> <span class="d_keyword">true</span>;
	}
	}

	<span class="d_keyword">class</span> CInfinite() : Concept
	{
	<span class="d_keyword">static</span> <span class="d_keyword">bool</span> Axioms(T)() {
	<span class="d_keyword">enum</span> empty = T.empty;
	<span class="d_keyword">return</span> !empty;
	}
	}

	<span class="d_keyword">class</span> CInfiniteInputRange(E) : CInputRange!E
	{
	<span class="d_keyword">mixin</span> CInfinite;
	}
	</pre>
	<p></p>

	</dd>
	<dt class="d_decl"><a name=".conceptDiagnostic"></a>template <a name="conceptDiagnostic"></a><span class="ddoc_psymbol">conceptDiagnostic</span>(R, string F, int L, C...)</dt>
	<dd>Prints error messages for why template instantiation failed.
	<p></p>
	<b>Examples:</b><br><pre class="d_code"><span class="d_keyword">bool</span> DoStuff(R)(R infRange) <span class="d_keyword">if</span> ( isConcept!(R, CInfiniteInputRange!string))
	{
	<span class="d_keyword">return</span> <span class="d_keyword">true</span>;
	}

	<span class="d_keyword">bool</span> DoStuff(R)(R infRange) <span class="d_keyword">if</span> ( isConcept!(R, COutputRange!string))
	{
	<span class="d_keyword">return</span> <span class="d_keyword">true</span>;
	}

	<span class="d_comment">//Example of using conceptDiagnostic
	</span><span class="d_keyword">bool</span> DoStuff(R, string F = <span class="d_keyword">__FILE__</span>, size_t L = <span class="d_keyword">__LINE__</span> )(R infRange)
	{
	<span class="d_keyword">mixin</span> <span class="d_psymbol">conceptDiagnostic</span>!(R, F, L, COutputRange!string, CInfiniteInputRange!string);
	<span class="d_keyword">return</span> <span class="d_keyword">false</span>;
	}
	</pre>
	<p></p>

	</dd>
	<dt class="d_decl"><a name=".Concept"></a>class <a name="Concept"></a><span class="ddoc_psymbol">Concept</span>;
	</dt>
	<dd>Base class for Concepts. All Concepts should derive from this, or another concept.<p></p>

	</dd>
	</dl>

	</div><!--/content-->


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	Copyright Shammah Chancellor 2014- .

	\|
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