headers/private/shared/TypeOperation.h

   1 /*
   2  * Copyright 2014, Haiku, Inc. All Rights Reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Based on TypeOp in "C++-Templates, The Complete Guide", which is
   6  * Copyright 2003 by Pearson Education, Inc.
   7  */
   8 #ifndef _TYPE_OPERATION_H
   9 #define _TYPE_OPERATION_H
  10
  11 namespace BPrivate {
  12
  13
  14 // Generic type conversion operations.
  15 template<typename T>
  16 class TypeOperation {
  17 public:
  18         typedef T                                       ArgT;
  19         typedef T                                       BareT;
  20         typedef T const                         ConstT;
  21
  22         typedef T&                                      RefT;
  23         typedef T&                                      BareRefT;
  24         typedef T const&                        ConstRefT;
  25 };
  26
  27
  28 // Specialization for constant types.
  29 template<typename T>
  30 class TypeOperation<T const> {
  31 public:
  32         typedef T const                         ArgT;
  33         typedef T                                       BareT;
  34         typedef T const                         ConstT;
  35
  36         typedef T const&                        RefT;
  37         typedef T&                                      BareRefT;
  38         typedef T const&                        ConstRefT;
  39 };
  40
  41
  42 // Specialization for reference types.
  43 template<typename T>
  44 class TypeOperation<T&> {
  45 public:
  46         typedef T&                                                                      ArgT;
  47         typedef typename TypeOperation<T>::BareT        BareT;
  48         typedef T const                                                         ConstT;
  49
  50         typedef T&                                                                      RefT;
  51         typedef typename TypeOperation<T>::BareRefT     BareRefT;
  52         typedef T const&                                                        ConstRefT;
  53 };
  54
  55
  56 // Specialization for void.
  57 template<>
  58 class TypeOperation<void> {
  59 public:
  60         typedef void                            ArgT;
  61         typedef void                            BareT;
  62         typedef void const                      ConstT;
  63
  64         typedef void                            RefT;
  65         typedef void                            BareRefT;
  66         typedef void                            ConstRefT;
  67 };
  68
  69
  70 }       // namespace BPrivate
  71
  72
  73 using BPrivate::TypeOperation;
  74
  75
  76 #endif  // _TYPE_OPERATION_H