Function parse_ipv6_literal 

pub fn parse_ipv6_literal(s: &str) -> Option<[u8; 16]>

Parses an IPv6 literal into network-order octets.

Supports standard colon-hex notation (RFC 4291) with :: compression.

Limitations

• IPv4-mapped/embedded forms (e.g. ::ffff:192.168.1.1) are not supported; only pure colon-hex notation is accepted.
• Zone IDs (e.g. fe80::1%eth0) are not supported; the zone identifier must be stripped before calling this function.

Example

assert_eq!(
    parse_ipv6_literal("2001:0db8:0000:0000:0000:ff00:0042:8329"),
    Some([
        0x20, 0x01, 0x0d, 0xb8, 0x00, 0x00, 0x00, 0x00,
        0x00, 0x00, 0xff, 0x00, 0x00, 0x42, 0x83, 0x29,
    ])
);

// Compressed forms
assert_eq!(
    parse_ipv6_literal("::1"),
    Some([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1])
);
assert_eq!(
    parse_ipv6_literal("fe80::5054:ff:fe12:3456"),
    Some([
        0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
        0x50, 0x54, 0x00, 0xff, 0xfe, 0x12, 0x34, 0x56,
    ])
);

// Loopback
assert_eq!(
    parse_ipv6_literal("::1"),
    Some([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1])
);