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| <H2>5.3 Boolean Vectors</H2> |
| <A NAME="idx95"><!></A> |
| <A NAME="idx96"><!></A> |
| <P>In the C++ Standard Library, <B><I><A HREF="../stdlibref/vector.html">vector</A></I></B>s of bit values (boolean 1/0 values) are handled as a special case, so that the values can be efficiently packed with several elements to a word. The operations for a boolean <B><I>vector</I></B>, <B><I>vector<bool></I></B>, are a superset of those for an ordinary <B><I>vector</I></B>, only the implementation is more efficient.</P> |
| <A NAME="idx97"><!></A> |
| <P>One new member function added to the boolean <B><I><A HREF="../stdlibref/vector.html">vector</A></I></B> datatype is <SAMP>flip()</SAMP>. When invoked, this function inverts all the bits of the <B><I>vector</I></B>. Boolean <B><I>vector</I></B>s also return as reference an internal value that also supports the <SAMP>flip()</SAMP> member function:</P> |
| |
| <UL><PRE> |
| std::vector<bool> bvec(27); |
| bvec.flip(); // flip all values |
| bvec[17].flip(); // flip bit 17 |
| </PRE></UL> |
| <P>The <B><I><A HREF="../stdlibref/vector.html">vector<bool></A></I></B> also supports an additional <SAMP>swap()</SAMP> member function that allows swapping the values indicated by a pair of references: </P> |
| |
| <UL><PRE> |
| bvec.swap(bvec [17], bvec [16]); |
| </PRE></UL> |
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