implement net.Error interface for stream deadline expiration errors

stream.go

@@ -1,9 +1,9 @@
 package quic
 
 import (
-	"errors"
 	"fmt"
 	"io"
+	"net"
 	"sync"
 	"time"
 
@@ -55,7 +55,13 @@ type stream struct {
 	flowControlManager flowcontrol.FlowControlManager
 }
 
-var errDeadline = errors.New("deadline exceeded")
+type deadlineError struct{}
+
+func (deadlineError) Error() string   { return "deadline exceeded" }
+func (deadlineError) Temporary() bool { return true }
+func (deadlineError) Timeout() bool   { return true }
+
+var errDeadline net.Error = &deadlineError{}
 
 // newStream creates a new Stream
 func newStream(StreamID protocol.StreamID,