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<Title>BasicMatrix</Title>
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<H1><A NAME="concept:BasicMatrix"></A>
BasicMatrix
</H1>

The BasicMatrix concept provides a minimalist interface for
accessing elements from a 2 dimensional table of values.


<H3>Refinement of</H3>

none

<h3>Notation</h3>

<Table>
<TR>
<TD>{<tt>M,I,V</tt>}</TD>
<TD>The matrix, index, and values types that together model the BasicMatrix concept.</TD>
</TR>

<TR>
<TD><tt>A</tt></TD>
<TD>An object of type <tt>M</tt>.</TD>
</TR>

<TR>
<TD><tt>i, j</tt></TD>
<TD>Objects of type <tt>I</tt>.</TD>
</TR>

</table>

<H3>Associated Types</H3>

none

<h3>Valid Expressions</h3>

<Table border>

<tr>
<td><a name="sec:elt-access"><TT>A[i][j]</TT></a></TD>
<TD>Returns a reference to the element object stored at index <tt>(i,j)</tt><br>
Return type: <TT>V&amp;</TT> for mutable <tt>A</tt> or <TT>const V&amp;</TT>
for constant <tt>A</tt>.
</TD>
</TR>

</table>

<H3>Complexity guarantees</H3>

Element access is constant time.

<H3>Concept Checking Class</H3>

<pre>
  template &lt;class M, class I, class V&gt;
  struct BasicMatrixConcept
  {
    void constraints() {
      V&amp; elt = A[i][j];
      const_constraints(A);
      ignore_unused_variable_warning(elt);      
    }
    void const_constraints(const M&amp; A) {
      const V&amp; elt = A[i][j];
      ignore_unused_variable_warning(elt);      
    }
    M A;
    I i, j;
  };
</pre>

<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>)
</TD></TR></TABLE>

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