src/base/TypeTraits.h

   1 /*
   2  * Copyright (C) 1996-2022 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_SRC_BASE_TYPETRAITS_H
  10 #define SQUID_SRC_BASE_TYPETRAITS_H
  11
  12 namespace TypeTraits_ { // a hack to prevent "unintended ADL"
  13
  14 // TODO: Extract reusable paradigms into other mixins (e.g., NonCopyable).
  15 /// convenience base for any class with pure virtual method(s)
  16 class Interface
  17 {
  18 public:
  19     // ensures proper destruction via pointers to base interface classes
  20     virtual ~Interface() = default;
  21
  22     // prohibits copy/move assignment to prevent accidental object slicing
  23     Interface &operator=(const Interface &) = delete;
  24     Interface &operator=(Interface &&) = delete;
  25
  26 protected: // prevents accidental creation of Interface instances
  27
  28     // allows default-construction in kids
  29     constexpr Interface() = default;
  30
  31     // allows copy/move construction for kids convenience
  32     Interface(const Interface &) = default;
  33     Interface(Interface &&) = default;
  34 };
  35
  36 } // namespace TypeTraits_
  37
  38 using Interface = TypeTraits_::Interface;
  39
  40 #endif /* SQUID_SRC_BASE_TYPETRAITS_H */
  41