Golang function to insert in sorted array

go-sort-insert.go

// Mytype must implement Less func.

func SortedInsert (s []Mytype, f Mytype) []Mytype {
    l:=len(s)
    if l==0 { return [f] }

    i := sort.Search(l, func(i int) bool { return s[i].Less(f)})
    if i==l {  // not found = new value is the smallest
        return append([f],s)
    }
    if i==l-1 { // new value is the biggest
        return append(s[0:l],f)
    }
    return append(s[0:l],f,s[l+1:])
}

append(s[0:l],f,s[l+1:])
where l=len(s) ?
Guess you meant
append(s[0:i],f,s[i+1:])

Another solution without conditionals (not needed, works on arrays of any size, including empty) and Less function

func insertSort(data []Example, el Example) []Example {
	index := sort.Search(len(data), func(i int) bool { return data[i].field > el.field })
	data = append(data, Example{})
	copy(data[index+1:], data[index:])
	data[index] = el
	return data
}

Go playground example