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<Title>Boost Graph Library: ColorValue Concept</Title>
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<H1><A NAME="concept:ColorValue"></A>
ColorValue
</H1>

<P>
This concept describes the requirements for the type used for color
values, as in for coloring a graph during a breath-first search to
mark which vertices have been visited.

<P>

<h3>Refinement of</h3> <a
href="http://www.sgi.com/tech/stl/EqualityComparable.html">EqualityComparable</a>
and <a
href="http://www.sgi.com/tech/stl/DefaultConstructible.html">DefaultConstructible</a>


<h3>Notation</h3>

<Table>
<TR>
<TD><tt>T</tt></TD>
<TD>A type that is a model of ColorValue.</TD>
</TR>

<TR>
<TD><tt>cv</tt></TD>
<TD>An object of type <tt>T</tt>.</TD>
</TR>

</table>

<h3>Valid Expressions</h3>

<Table border>

<tr>
<th>Name</th><th>Expression</th><th>Return Type</th><th>Description</th>
</tr>

<tr>
<td>Get Color White </td>
<TD><TT>color_traits&lt;T&gt;::white()</TT></TD>
<TD><TT>T</TT></TD>
<TD>Returns an object that represents the color white.</TD>
</TR>

<tr>
<td>Get Color Gray </td>
<TD><TT>color_traits&lt;T&gt;::gray()</TT></TD>
<TD><TT>T</TT></TD>
<TD>Returns an object that represents the color gray.</TD>
</TR>

<tr>
<td>Get Color Black </td>
<TD><TT>color_traits&lt;T&gt;::black()</TT></TD>
<TD><TT>T</TT></TD>
<TD>Returns an object that represents the color black.</TD>
</TR>

</TABLE>

<P>
</LI>
</UL>

<h3>Models</h3>

<ul>
  <li><tt>default_color_type</tt> (in <a href="../../../boost/graph/properties.hpp"><tt>boost/graph/properties.hpp</tt>)
</ul>


<br>
<HR>
<TABLE>
<TR valign=top>
<TD nowrap>Copyright &copy; 2000-2001</TD><TD>
<A HREF="http://www.boost.org/people/jeremy_siek.htm">Jeremy Siek</A>,
Indiana University (<A
HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>)<br>
<A HREF="http://www.boost.org/people/liequan_lee.htm">Lie-Quan Lee</A>, Indiana University (<A HREF="mailto:llee@cs.indiana.edu">llee@cs.indiana.edu</A>)<br>
<A HREF="http://www.osl.iu.edu/~lums">Andrew Lumsdaine</A>,
Indiana University (<A
HREF="mailto:lums@osl.iu.edu">lums@osl.iu.edu</A>)
</TD></TR></TABLE>

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