src/scss/bootstrap-4.0.0-alpha.6/scss/utilities/_sizing.scss

   1 // Width and height
   2
   3 @each $prop, $abbrev in (width: w, height: h) {
   4   @each $size, $length in $sizes {
   5     .#{$abbrev}-#{$size} { #{$prop}: $length !important; }
   6   }
   7 }
   8
   9 .mw-100 { max-width: 100% !important; }
  10 .mh-100 { max-height: 100% !important; }