Mixins

_mixins.scss

@mixin position($top: false, $left: false, $bottom: false, $right: false) {
	position: absolute;
	@if type_of($top) == number {
		top: $top;
	}
	@if type_of($left) == number {
		left: $left;
	}
	@if type_of($bottom) == number {
		bottom: $bottom;
	}
	@if type_of($right) == number {
		right: $right;
	}
}

// Examples
#my_div {
	@include position($top: 0, $right: 0); //set any side distance
}

@mixin border-radius($radius: false, $topleft: false, $topright: false, $bottomright: false, $bottomleft: false) {
	@if type_of($radius) == number {
		-webkit-border-radius: $radius;
		-moz-border-radius: $radius;
		border-radius: $radius;
	}
	@if type_of($topleft) == number {
		-webkit-border-top-left-radius: $topleft;
		-moz-border-radius-topleft: $topleft;
		border-top-left-radius: $topleft;
	}
	@if type_of($topright) == number {
		-webkit-border-top-right-radius: $topright;
		-moz-border-radius-topright: $topright;
		border-top-right-radius: $topright;
	}
	@if type_of($bottomright) == number {
		-webkit-border-bottom-right-radius: $bottomright;
		-moz-border-radius-bottomright: $bottomright;
		border-bottom-right-radius: $bottomright;
	}
	@if type_of($bottomleft) == number {
		-webkit-border-bottom-left-radius: $bottomleft;
		-moz-border-radius-bottomleft: $bottomleft;
		border-bottom-left-radius: $bottomleft;
	}
}

// Examples
#my_div {
	@include border-radius(20px); //set all corners
}
#my_div {
	@include border-radius($topleft: 20px); //set any of the specific corners
}