less size mixin

size mixins

//less mixin
.size(@string) {
	@w: ~`(function(a){ return a.split(" x ").shift()+"px"; })( @{string})`;
	@h: ~`(function(a){ return a.split(" x ").pop()+"px"; })( @{string})`;
	width:@w;
	height:@h;
}

//usage
#myId{
  .size("225 x 305");
}

//result
#myId{
  width:225px;
  height:305px;
}