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operator< (<valarray>)

Tests whether the elements of one valarray are less than the elements of an equally sized valarray or whether all the elements of a valarray are greater or less than a specified value.

template<class Type>
   valarray<bool> operator<(
      const valarray<Type>& _Left,
      const valarray<Type>& _Right
   );
template<class Type>
   valarray<bool> operator<(
      const valarray<Type>& _Left,
      const Type& _Right
   );
template<class Type>
   valarray<bool> operator<(
      const Type& _Left,
      const valarray<Type>& _Right
   );

_Left

The first of the two valarrays whose elements are to be compared or a specified value to be compared with each element of a valarray.

_Right

The second of the two valarrays whose elements are to be compared or a specified value to be compared with each element of a valarray.

A valarray of Boolean values, each of which is:

  • true if the _Left element or value is less than the corresponding _Right element or value.

  • false if the _Left element or value is not less than the corresponding _Right element or value.

If the number of elements two valarrays is not equal, the result is undefined.

// valarray_op_lt.cpp
// compile with: /EHsc
#include <valarray>
#include <iostream>

int main( )
{
   using namespace std;
   int i;

   valarray<int> vaL ( 10 ), vaR ( 10 );
   valarray<bool> vaNE ( 10 );
   for ( i = 0 ; i < 10 ; i += 2 )
      vaL [ i ] =  -i;
   for ( i = 1 ; i < 10 ; i += 2 )
      vaL [ i ] =  i;
   for ( i = 0 ; i < 10 ; i++ )
      vaR [ i ] =  i;
   
   cout << "The initial Left valarray is: ( ";
      for ( i = 0 ; i < 10 ; i++ )
         cout << vaL [ i ] << " ";
   cout << ")." << endl;

   cout << "The initial Right valarray is: ( ";
      for ( i = 0 ; i < 10 ; i++ )
         cout << vaR [ i ] << " ";
   cout << ")." << endl;

   vaNE = ( vaL < vaR );
   cout << "The element-by-element result of "
        << "the less-than comparson test is the\n valarray: ( ";
      for (i = 0 ; i < 10 ; i++ )
         cout << vaNE [ i ] << " ";
   cout << ")." << endl;
}
The initial Left valarray is: ( 0 1 -2 3 -4 5 -6 7 -8 9 ).
The initial Right valarray is: ( 0 1 2 3 4 5 6 7 8 9 ).
The element-by-element result of the less-than comparson test is the
 valarray: ( 0 0 1 0 1 0 1 0 1 0 ).

Header: <valarray>

Namespace: std

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