valarray::operator<<=
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# valarray::operator<<=

Visual Studio 2005

Left-shifts the bits for each element of a valarray operand a specified number of positions or by an element-wise amount specified by a second valarray.

valarray<Type>& operator<<=(
const valarray<Type>& _Right
);
valarray<Type>& operator<<=(
const Type& _Right
);

#### Parameters

_Right

The value indicating the amount of left shift or valarray whose elements indicate the element-wise amount of left shift.

## Return Value

A valarray whose elements have been shifted left the amount specified in _Right.

## Remarks

Signed numbers have their signs preserved.

## Example

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

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

valarray<int> vaL ( 8 ), vaR ( 8 );
for ( i = 0 ; i < 8 ; i += 2 )
vaL [ i ] =  1;
for ( i = 1 ; i < 8 ; i += 2 )
vaL [ i ] =  -1;
for ( i = 0 ; i < 8 ; i++ )
vaR [ i ] =  i;

cout << "The initial operand valarray is: ( ";
for ( i = 0 ; i < 8 ; i++ )
cout << vaL [ i ] << " ";
cout << ")." << endl;

cout << "The _Right valarray is: ( ";
for ( i = 0 ; i < 8 ; i++ )
cout << vaR [ i ] << " ";
cout << ")." << endl;

vaL <<= vaR;
cout << "The element-by-element result of "
<< "the left shift\n on the operand array is the valarray:\n ( ";
for ( i = 0 ; i < 8 ; i++ )
cout << vaL [ i ] << " ";
cout << ")." << endl;
}

#### Output

The initial operand valarray is: ( 1 -1 1 -1 1 -1 1 -1 ).
The _Right valarray is: ( 0 1 2 3 4 5 6 7 ).
The element-by-element result of the left shift
on the operand array is the valarray:
( 1 -2 4 -8 16 -32 64 -128 ).