spow

import des.math.linear.vector;
assertEq( spow( vec3( 1, 2, 3 ), 3 ), vec3( 1, 8, 27 ) );
foreach( i; 0 .. 16 ) assertEq( spow( 10, i ), 10 ^^ i,
        format( "spow fails (%%s != %%s) with i: %s",  i ) );