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<TITLE>Boost Numeric Conversion Library - Bounds</TITLE>
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<H1 ALIGN="center">Boost Numeric Conversion Library</H1>
<H1><A HREF="http://www.boost.org">Header </A><A
HREF="../../../../boost/numeric/conversion/bounds.hpp">boost/numeric/conversion/bounds.hpp</A></H1>
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<H2>Contents</H2>
<UL>
<LI><A HREF="#introduction">Introduction</A></LI>
<LI><A HREF="#bounds"><code>template class bounds<N></CODE></A></LI>
<LI><A HREF="#examples">Examples</A></LI>
<!--<LI><A HREF="#implementation">Implementation</A></LI>-->
<!--<LI><A HREF="#portability">Portability</A></LI>-->
</UL> <HR>
<H2><A NAME="introduction">Introduction</A></H2>
<P>To determine the ranges of numeric types with std:: numeric_limits
[18.2.1], different syntax have to be used depending on numeric type.
Specifically, numeric_limits<T>::min() for integral types returns the
minimum finite value, whereas for floating point types it returns the minimum
positive normalized value. The difference in semantics makes client code
unnecessarily complex and error prone. <BR> <BR>
boost::numeric::bounds<> provides a consistent interface for retrieving
the maximum finite value, the minimum finite value and the minimum positive
normalized value (0 for integral types) for numeric types. The selection of
implementation is performed at compile time, so there is no runtime overhead.
<BR>
<BR> </P> <HR>
<H2><A NAME="bounds"><CODE>traits class bounds<N></CODE></A></H2>
<BLOCKQUOTE>
<PRE>template<class N>
struct bounds
{
static N lowest () { return <i>implementation_defined</i>; }
static N highest () { return <i>implementation_defined</i>; }
static N smallest() { return <i>implementation_defined</i>; }
};</PRE>
</BLOCKQUOTE>
<H3>Members</H3>
<PRE>lowest()</PRE>
<P>Returns the minimum finite value, equivalent to
numeric_limits<T>::min() when T is an integral type, and to
-numeric_limits<T>::max() when T is a floating point type. </P>
<PRE>highest()</PRE>
<P>Returns the maximum finite value, equivalent to
numeric_limits<T>::max(). </P>
<PRE>smallest()</PRE>
<P>Returns the smallest positive normalized value for floating point types with
denormalization, or returns 0 for integral types. <BR>
<BR>
</P> <HR>
<H2><A NAME="examples">Examples</A></H2>
<P>The following example demonstrates the use of numeric::bounds<> and the
equivalent code using numeric_limits: </P>
<BLOCKQUOTE>
<PRE>#include <iostream>
#include <boost/numeric/conversion/bounds.hpp>
#include <boost/limits.hpp>
int main() {
std::cout << "numeric::bounds versus numeric_limits example.\n";
std::cout << "The maximum value for float:\n";
std::cout << boost::numeric::bounds<float>::highest() << "\n";
std::cout << std::numeric_limits<float>::max() << "\n";
std::cout << "The minimum value for float:\n";
std::cout << boost::numeric::bounds<float>::lowest() << "\n";
std::cout << -std::numeric_limits<float>::max() << "\n";
std::cout << "The smallest positive value for float:\n";
std::cout << boost::numeric::bounds<float>::smallest() << "\n";
std::cout << std::numeric_limits<float>::min() << "\n";
return 0;
}</PRE>
</BLOCKQUOTE>
<hr>
<P>Back to <A HREF="index.html">Numeric Conversion library index</A></P>
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<P>Revised 23 June 2004</P>
<p> Copyright Fernando Luis Cacciola Carballal, 2004</p>
<p> Use, modification, and distribution are subject to the Boost Software
License, Version 1.0. (See accompanying file <a href="../../../../LICENSE_1_0.txt">
LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
www.boost.org/LICENSE_1_0.txt</a>)</p>
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