feat: new implementations

ip/ipv6.go

@@ -0,0 +1,28 @@
+package ip
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/RomiChan/syncx"
+)
+
+var IsIPv6Available = syncx.Lazy[bool]{Init: func() bool {
+	ctx, cancel := context.WithTimeout(context.Background(), 4*time.Second)
+	defer cancel()
+	req, err := http.NewRequestWithContext(ctx, "GET", "http://v6.ipv6-test.com/json/widgetdata.php?callback=?", nil)
+	if err != nil {
+		return false
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return false
+	}
+	_ = resp.Body.Close()
+	return true
+}}
+
+func init() {
+	go IsIPv6Available.Get()
+}