lambda : fabs( x - y )< eps - Boost-users

11 Mar 2011


      I'm submitting this in case someone easily spots a less verbose 
representation of fabs( x - y )< eps than the one shown below and would 
like to share it. Using lambda (or variants) only (I know I can write my 
own functor class). Thanks.

#include <cmath>
#include 
#include 
#include 
#include 

typedef boost::function f1_;
typedef boost::function f2_;
typedef boost::function g_;

double eps = boost::numeric::bounds<double>::smallest();
f2_ f2 = lambda::bind( f1_( fabs ), lambda::_1 - lambda::_2 ) ;
g_ g = ( eps > lambda::_1 );

BOOST_ASSERT( lambda::bind( g, lambda::bind( f2, lambda::_1, lambda::_2 
) )( 0.0, 0 * eps ) );
BOOST_ASSERT( !lambda::bind( g, lambda::bind( f2, lambda::_1, lambda::_2 
) )( 0.0,  eps ) );

lambda : fabs( x - y )< eps

er

Steven Watanabe

er

Thomas Heller

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