text: /*
   * Copyright 2017 Facebook, Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #pragma once
  
  namespace folly {
  
  class SocketAddressTestHelper {
   public:
    static constexpr const char* kLoopbackAddrIPv4 = "127.0.0.1";
    static constexpr const char* kLoopbackAddrIPv6 = "::1";
  
    //  https://developers.google.com/speed/public-dns/docs/using?hl=en
    static constexpr const char* kGooglePublicDnsAName =
        "google-public-dns-a.google.com";
    static constexpr const char* kGooglePublicDnsBName =
        "google-public-dns-b.google.com";
    static constexpr const char* kGooglePublicDnsAAddrIPv4 = "8.8.8.8";
    static constexpr const char* kGooglePublicDnsBAddrIPv4 = "8.8.4.4";
    static constexpr const char* kGooglePublicDnsAAddrIPv6 =
        "2001:4860:4860::8888";
    static constexpr const char* kGooglePublicDnsBAddrIPv6 =
        "2001:4860:4860::8844";
  
    static bool isIPv4Enabled();
    static bool isIPv6Enabled();
  
   private:
    static bool isFamilyOfAddrEnabled(const char* addr);
  };
  }
  