slices.go
func (s StringSlice) IndexOfIgnoreCase(str string) int {
	str = strings.ToLower(str)
	for i, v := range s {
		if str == strings.ToLower(v) {
			return i
		}
	}

	return -1
}
func (s StringSlice) IndexOfIgnoreCase(str string) int {
	str = strings.ToLower(str)
	for i, v := range s {
		if str == strings.ToLower(v) {
			return i
		}
	}

	return -1
}
func ( s StringSlice ) IndexOfIgnoreCase ( str string ) int { str = strings . ToLower ( str ) for i , v := range s { if str == strings . ToLower ( v ) { return i } } return - 1 }
// IndexOfIgnoreCase looks for specified string, disregarding letter casing,
// into current slice.
IndexOfIgnoreCase looks for specified string disregarding letter casing into current slice .