getpeername

pub fn getpeername(sock: socket_t, addr: *sockaddr, addrlen: *socklen_t) GetSockNameError!void {
    if (native_os == .windows) {
        @compileError("use std.Io instead");
    } else {
        const rc = system.getpeername(sock, addr, addrlen);
        switch (errno(rc)) {
            .SUCCESS => return,
            else => |err| return unexpectedErrno(err),

            .BADF => unreachable, // always a race condition
            .FAULT => unreachable,
            .INVAL => unreachable, // invalid parameters
            .NOTSOCK => return error.FileDescriptorNotASocket,
            .NOBUFS => return error.SystemResources,
            .NOTCONN => return error.SocketUnconnected,
        }
    }
}