.ie-rotate-via-degrees(@degrees) {
    /* IE6-IE8 */
    @radians: ~`parseInt("@{degrees}") * Math.PI * 2 / 360`;
    @costheta: ~`Math.cos("@{radians}")`;
    @sintheta: ~`Math.sin("@{radians}")`;
    @negsintheta: ~`"@{sintheta}" * -1`;
    -ms-filter: "progid:DXImageTransform.Microsoft.Matrix(sizingMethod='auto expand', M11=@{costheta}, M12=@{negsintheta}, M21=@{sintheta}, M22=@{costheta})";
    zoom: 1;
     :root & {
        filter: none;
    }
}

.iconfont-size-under-12px(@size, @rotate: 0deg) {
    display: inline-block;
    @font-scale: unit(@size / 12px);
    font-size: @font-size-base; // ie8-9
    font-size:~"@{size} \9"; // lesshint duplicateProperty: false
    transform: scale(@font-scale) rotate(@rotate);
    .ie-rotate-via-degrees(@rotate);
     :root & {
        font-size: @font-size-base; // reset ie9 and above
    }
}