You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: addrselect.go
    path of file: ./repos/gccrs/libgo/go/net
    
    the code of the file until where you have to start completion: // Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris

// Minimal RFC 6724 add
    
func classifyScope(ip IP) scope {
	if ip.IsLoopback() || ip.IsLinkLocalUnicast() {
		return scopeLinkLocal
	}
	ipv6 := len(ip) == IPv6len && ip.To4() == nil
	if ipv6 && ip.IsMulticast() {
		return scope(ip[1] & 0xf)
	}
	// Site-local addresses are defined in RFC 3513 section 2.5.6
	// (and deprecated in RFC 3879).
	if ipv6 && ip[0] == 0xfe && ip[1]&0xc0 == 0xc0 {
		return scopeSiteLocal
	}
	return scopeGlobal
}