Struct QuicTarget 

pub struct QuicTarget {
    pub addr: SocketAddr,
    pub server_name: String,
}

Where packets go, and whose certificate to expect when they arrive.

Two fields and not one host:port string, because they are two different things and a public relay is where that stops being pedantry. The socket layer needs an address it can send to; the TLS layer needs the name a certificate was issued for. Deriving the second from the first — which is what a single string forces — leaves only bad options: dial the hostname and parse::<SocketAddr>() rejects it, or resolve first and then validate a public relay’s certificate against an IP literal that no CA ever put in a SAN. dial_quic is where both are avoided.

Fields

addr: SocketAddr

The address packets are sent to. Already resolved — nothing in this module does DNS on it.

server_name: String

The name offered in SNI and validated against the server’s certificate.

An IP literal is legal and is what a loopback peer holding an IP-SAN certificate wants; a hostname is what a public relay wants. Keeping it separate is what lets one caller ask for both against one address.