Placeholder mixins

_mixins.scss

/*
SECTION PLACEHOLDERS MIXINS
Usage:
    input {
        @include placeholder {
          //STYLES here
        }
    }
Output
    input::-webkit-input-placeholder {
    //STYLES here
    }
    input:-moz-placeholder {
      //STYLES here
    }
    input::-moz-placeholder {
      //STYLES here
    }
    input:-ms-input-placeholder {
      //STYLES here
    }
}*/

@mixin placeholder {
  &::-webkit-input-placeholder {
    @content;
  }
  &:-moz-placeholder {
    @content;
  }
  &::-moz-placeholder {
    @content;
  }
  &:-ms-input-placeholder {
    @content;
  }
}