import std.stdio;

​

struct TcpSocket

{

    int send(ubyte[] data, int len) { writeln("TcpSocket send"); return len; }

    int recv(ubyte[] buff, int len) { writeln("TcpSocket recv"); return len; }

}

​

struct UdpSocket

{

    int send(ubyte[] data, int len) { writeln("UdpSocket send"); return len; }

    int recv(ubyte[] buff, int len) { writeln("UdpSocket recv"); return len; }

}

​

struct UnixSocket

{

    int send(ubyte[] data, int len) { writeln("UdpSocket send"); return len; }

    int recv(ubyte[] buff, int len) { writeln("UdpSocket recv"); return len; }

}

​

struct NotASocket { }

​

void Use(T)(T socket)

{

    socket.send([], 0);

    socket.recv([], 0);

}

​

void main()

{

    TcpSocket socket;

    socket.Use();   // Works out of the box without any interface boilerplate

    NotASocket noSocket;

    //noSocket.Use(); // Error: no property `send`/`recv` for type `NotASocket`

}