21 Internet protocol [internet]

The class address is a version-independent representation for an IP address. An object of class address holds either an IPv4 address, an IPv6 address, or no valid address.

namespace std {
namespace experimental {
namespace net {
inline namespace v1 {
namespace ip {

  class address
  {
  public:
    // [internet.address.cons], constructors:
    constexpr address() noexcept;
    constexpr address(const address& a) noexcept;
    constexpr address(const address_v4& a) noexcept;
    constexpr address(const address_v6& a) noexcept;

    // [internet.address.assign], assignment:
    address& operator=(const address& a) noexcept;
    address& operator=(const address_v4& a) noexcept;
    address& operator=(const address_v6& a) noexcept;

    // [internet.address.members], members:
    constexpr bool is_v4() const noexcept;
    constexpr bool is_v6() const noexcept;
    constexpr address_v4 to_v4() const;
    constexpr address_v6 to_v6() const;
    constexpr bool is_unspecified() const noexcept;
    constexpr bool is_loopback() const noexcept;
    constexpr bool is_multicast() const noexcept;
    template<class Allocator = allocator<char>>
      basic_string<char, char_traits<char>, Allocator>
        to_string(const Allocator& a = Allocator()) const;

  private:
    address_v4 v4_; // exposition only
    address_v6 v6_; // exposition only
  };

  // [internet.address.comparisons], address comparisons:
  constexpr bool operator==(const address& a, const address& b) noexcept;
  constexpr bool operator!=(const address& a, const address& b) noexcept;
  constexpr bool operator< (const address& a, const address& b) noexcept;
  constexpr bool operator> (const address& a, const address& b) noexcept;
  constexpr bool operator<=(const address& a, const address& b) noexcept;
  constexpr bool operator>=(const address& a, const address& b) noexcept;

  // [internet.address.creation], address creation:
  address make_address(const char* str);
  address make_address(const char* str, error_code& ec) noexcept;
  address make_address(const string& str);
  address make_address(const string& str, error_code& ec) noexcept;
  address make_address(string_view str);
  address make_address(string_view str, error_code& ec) noexcept;

  // [internet.address.io], address I/O:
  template<class CharT, class Traits>
    basic_ostream<CharT, Traits>& operator<<(
      basic_ostream<CharT, Traits>& os, const address& addr);

} // namespace ip
} // inline namespace v1
} // namespace net
} // namespace experimental
} // namespace std

address satisfies the requirements for Destructible (C++ 2014 [destructible]), CopyConstructible (C++ 2014 [copyconstructible]), and CopyAssignable (C++ 2014 [copyassignable]).