valarray--slice函数

函数说明
slice( );
slice(
size_t _StartIndex,
size_t _Len,
size_t _Stride
);

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

valarray va ( 20 ), vaResult;
for ( i = 0 ; i < 20 ; i+=1 )
va [ i ] = 2 * (i + 1 );

cout << “The operand valarray va is:\n( “;
for ( i = 0 ; i < 20 ; i++ )
cout << va [ i ] << ” “;
cout << “).” << endl;

slice vaSlice ( 1 , 7 , 3 );
vaResult = va [ vaSlice ];

cout << “\nThe slice of valarray va is vaResult:”
<< “\nva[slice( 1, 7, 3)] = ( “;
for ( i = 0 ; i < 7 ; i++ )
cout << vaResult [ i ] << ” “;
cout << “).” << endl;
}