1/*
2 *
3 * Copyright (c) 2003
4 * Francois Dumont
5 *
6 * This material is provided "as is", with absolutely no warranty expressed
7 * or implied. Any use is at your own risk.
8 *
9 * Permission to use or copy this software for any purpose is hereby granted
10 * without fee, provided the above notices are retained on all copies.
11 * Permission to modify the code and to distribute modified code is granted,
12 * provided the above notices are retained, and a notice that the code was
13 * modified is included with the above copyright notice.
14 *
15 */
16
17
18#ifndef _STLP_TYPE_MANIPS_H
19#define _STLP_TYPE_MANIPS_H
20
21_STLP_BEGIN_NAMESPACE
22
23struct __true_type {};
24struct __false_type {};
25
26#if defined (_STLP_USE_NAMESPACES) && !defined (_STLP_DONT_USE_PRIV_NAMESPACE)
27_STLP_MOVE_TO_PRIV_NAMESPACE
28using _STLP_STD::__true_type;
29using _STLP_STD::__false_type;
30_STLP_MOVE_TO_STD_NAMESPACE
31#endif
32
33//bool to type
34template <int _Is>
35struct __bool2type
36{ typedef __true_type _Ret; };
37
38_STLP_TEMPLATE_NULL
39struct __bool2type<1> { typedef __true_type _Ret; };
40
41_STLP_TEMPLATE_NULL
42struct __bool2type<0> { typedef __false_type _Ret; };
43
44//type to bool
45template <class __bool_type>
46struct __type2bool { enum {_Ret = 1}; };
47
48_STLP_TEMPLATE_NULL
49struct __type2bool<__true_type> { enum {_Ret = 1}; };
50
51_STLP_TEMPLATE_NULL
52struct __type2bool<__false_type> { enum {_Ret = 0}; };
53
54//Negation
55template <class _BoolType>
56struct _Not { typedef __false_type _Ret; };
57
58_STLP_TEMPLATE_NULL
59struct _Not<__false_type> { typedef __true_type _Ret; };
60
61// logical and of 2 predicated
62template <class _P1, class _P2>
63struct _Land2 { typedef __false_type _Ret; };
64
65_STLP_TEMPLATE_NULL
66struct _Land2<__true_type, __true_type> { typedef __true_type _Ret; };
67
68// logical and of 3 predicated
69template <class _P1, class _P2, class _P3>
70struct _Land3 { typedef __false_type _Ret; };
71
72_STLP_TEMPLATE_NULL
73struct _Land3<__true_type, __true_type, __true_type> { typedef __true_type _Ret; };
74
75//logical or of 2 predicated
76template <class _P1, class _P2>
77struct _Lor2 { typedef __true_type _Ret; };
78
79_STLP_TEMPLATE_NULL
80struct _Lor2<__false_type, __false_type> { typedef __false_type _Ret; };
81
82// logical or of 3 predicated
83template <class _P1, class _P2, class _P3>
84struct _Lor3 { typedef __true_type _Ret; };
85
86_STLP_TEMPLATE_NULL
87struct _Lor3<__false_type, __false_type, __false_type> { typedef __false_type _Ret; };
88
89////////////////////////////////////////////////////////////////////////////////
90// class template __select
91// Selects one of two types based upon a boolean constant
92// Invocation: __select<_Cond, T, U>::Result
93// where:
94// flag is a compile-time boolean constant
95// T and U are types
96// Result evaluates to T if flag is true, and to U otherwise.
97////////////////////////////////////////////////////////////////////////////////
98// BEWARE: If the compiler do not support partial template specialization or nested template
99//classes the default behavior of the __select is to consider the condition as false and so return
100//the second template type!!
101
102#if defined (_STLP_CLASS_PARTIAL_SPECIALIZATION)
103#  if defined (__BORLANDC__)
104template <class _CondT, class _Tp1, class _Tp2>
105struct __selectT { typedef _Tp1 _Ret; };
106
107template <class _Tp1, class _Tp2>
108struct __selectT<__false_type, _Tp1, _Tp2> { typedef _Tp2 _Ret; };
109#  endif
110
111#  if !defined (__BORLANDC__) || (__BORLANDC__ >= 0x590)
112template <bool _Cond, class _Tp1, class _Tp2>
113struct __select { typedef _Tp1 _Ret; };
114
115template <class _Tp1, class _Tp2>
116struct __select<false, _Tp1, _Tp2> { typedef _Tp2 _Ret; };
117#  else
118template <bool _Cond, class _Tp1, class _Tp2>
119struct __select
120{ typedef __selectT<typename __bool2type<_Cond>::_Ret, _Tp1, _Tp2>::_Ret _Ret; };
121#  endif
122
123#else
124
125#  if defined (_STLP_MEMBER_TEMPLATE_CLASSES)
126template <int _Cond>
127struct __select_aux {
128  template <class _Tp1, class _Tp2>
129  struct _In {
130    typedef _Tp1 _Ret;
131  };
132};
133
134_STLP_TEMPLATE_NULL
135struct __select_aux<0> {
136  template <class _Tp1, class _Tp2>
137  struct _In {
138    typedef _Tp2 _Ret;
139  };
140};
141
142template <int _Cond, class _Tp1, class _Tp2>
143struct __select {
144  typedef typename __select_aux<_Cond>::_STLP_TEMPLATE _In<_Tp1, _Tp2>::_Ret _Ret;
145};
146#  else /* _STLP_MEMBER_TEMPLATE_CLASSES */
147//default behavior
148template <int _Cond, class _Tp1, class _Tp2>
149struct __select {
150  typedef _Tp2 _Ret;
151};
152#  endif /* _STLP_MEMBER_TEMPLATE_CLASSES */
153
154#endif /* _STLP_CLASS_PARTIAL_SPECIALIZATION */
155
156/* Rather than introducing a new macro for the following constrution we use
157 * an existing one (_STLP_DONT_SIMULATE_PARTIAL_SPEC_FOR_TYPE_TRAITS) that
158 * is used for a similar feature.
159 */
160#if !defined (_STLP_DONT_SIMULATE_PARTIAL_SPEC_FOR_TYPE_TRAITS) && \
161    (!defined (__GNUC__) || (__GNUC__ > 2))
162// Helper struct that will forbid volatile qualified types:
163#  if !defined (__BORLANDC__)
164struct _NoVolatilePointerShim { _NoVolatilePointerShim(const void*); };
165template <class _Tp>
166char _STLP_CALL _IsCopyableFun(bool, _NoVolatilePointerShim, _Tp const*, _Tp*); // no implementation is required
167char* _STLP_CALL _IsCopyableFun(bool, ...);       // no implementation is required
168
169template <class _Src, class _Dst>
170struct _Copyable {
171  static _Src* __null_src();
172  static _Dst* __null_dst();
173  enum { _Ret = (sizeof(_IsCopyableFun(false, __null_src(), __null_src(), __null_dst())) == sizeof(char)) };
174  typedef typename __bool2type<_Ret>::_Ret _RetT;
175};
176#  else
177template <class _Tp1, class _Tp2> struct _AreSameTypes;
178template <class _Tp> struct _IsUnQual;
179template <class _Src, class _Dst>
180struct _Copyable {
181  typedef typename _AreSameTypes<_Src, _Dst>::_Ret _Tr1;
182  typedef typename _IsUnQual<_Dst>::_Ret _Tr2;
183  typedef typename _Land2<_Tr1, _Tr2>::_Ret _RetT;
184  enum { _Ret = __type2bool<_RetT>::_Ret };
185};
186#  endif
187#else
188template <class _Src, class _Dst>
189struct _Copyable {
190  enum { _Ret = 0 };
191  typedef __false_type _RetT;
192};
193#endif
194
195/*
196 * The following struct will tell you if 2 types are the same and if copying memory
197 * from the _Src type to the _Dst type is right considering qualifiers. If _Src and
198 * _Dst types are the same unqualified types _Ret will be false if:
199 *  - any of the type has the volatile qualifier
200 *  - _Dst is const qualified
201 */
202template <class _Src, class _Dst>
203struct _AreCopyable {
204  enum { _Same = _Copyable<_Src, _Dst>::_Ret };
205  typedef typename _Copyable<_Src, _Dst>::_RetT _Ret;
206};
207
208template <class _Tp1, class _Tp2>
209struct _AreSameTypes {
210  enum { _Same = 0 };
211  typedef __false_type _Ret;
212};
213
214#if defined (_STLP_CLASS_PARTIAL_SPECIALIZATION)
215template <class _Tp>
216struct _AreSameTypes<_Tp, _Tp> {
217  enum { _Same = 1 };
218  typedef __true_type _Ret;
219};
220#endif
221
222#if !defined (_STLP_DONT_SIMULATE_PARTIAL_SPEC_FOR_TYPE_TRAITS)
223template <class _Src, class _Dst>
224struct _ConversionHelper {
225  static char _Test(bool, _Dst);
226  static char* _Test(bool, ...);
227  static _Src _MakeSource();
228};
229
230template <class _Src, class _Dst>
231struct _IsConvertible {
232  typedef _ConversionHelper<_Src*, const volatile _Dst*> _H;
233  enum { value = (sizeof(char) == sizeof(_H::_Test(false, _H::_MakeSource()))) };
234  typedef typename __bool2type<value>::_Ret _Ret;
235};
236
237#  if defined (__BORLANDC__)
238#    if (__BORLANDC__ < 0x590)
239template<class _Tp>
240struct _UnConstPtr { typedef _Tp _Type; };
241
242template<class _Tp>
243struct _UnConstPtr<_Tp*> { typedef _Tp _Type; };
244
245template<class _Tp>
246struct _UnConstPtr<const _Tp*> { typedef _Tp _Type; };
247#    endif
248
249#    if !defined (_STLP_QUALIFIED_SPECIALIZATION_BUG)
250template <class _Tp>
251struct _IsConst { typedef __false_type _Ret; };
252#    else
253template <class _Tp>
254struct _IsConst { typedef _AreSameTypes<_Tp, const _Tp>::_Ret _Ret; };
255#    endif
256
257#    if defined (_STLP_CLASS_PARTIAL_SPECIALIZATION) && !defined (_STLP_QUALIFIED_SPECIALIZATION_BUG)
258template <class _Tp>
259struct _IsConst <const _Tp> { typedef __true_type _Ret; };
260#    endif
261
262#    if (__BORLANDC__ < 0x590)
263template<class _Tp>
264struct _IsConst<_Tp*> { typedef _AreSameTypes<_Tp*, const _Tp*>::_Ret _Ret; };
265#    endif
266template <class _Tp>
267struct _IsVolatile { typedef _AreSameTypes<_Tp, volatile _Tp>::_Ret _Ret; };
268
269template<class _Tp>
270struct _IsUnQual {
271  typedef _IsConst<_Tp>::_Ret _Tr1;
272  typedef _IsVolatile<_Tp>::_Ret _Tr2;
273  typedef _Not<_Tr1>::_Ret _NotCon;
274  typedef _Not<_Tr2>::_Ret _NotVol;
275  typedef _Land2<_NotCon, _NotVol>::_Ret _Ret;
276};
277
278#    if !defined (_STLP_QUALIFIED_SPECIALIZATION_BUG)
279template <class _Tp> struct _UnQual { typedef _Tp _Type; };
280template <class _Tp> struct _UnQual<const _Tp> { typedef _Tp _Type; };
281template <class _Tp> struct _UnQual<volatile _Tp> { typedef _Tp _Type; };
282template <class _Tp> struct _UnQual<const volatile _Tp> { typedef _Tp _Type; };
283#    endif
284#  endif
285
286/* This struct is intended to say if a pointer can be convertible to an other
287 * taking into account cv qualifications. It shouldn't be instanciated with
288 * something else than pointer type as it uses pass by value parameter that
289 * results in compilation error when parameter type has a special memory
290 * alignment
291 */
292template <class _Src, class _Dst>
293struct _IsCVConvertible {
294#  if !defined (__BORLANDC__) || (__BORLANDC__ >= 0x590)
295  typedef _ConversionHelper<_Src, _Dst> _H;
296  enum { value = (sizeof(char) == sizeof(_H::_Test(false, _H::_MakeSource()))) };
297#  else
298  enum { _Is1 = __type2bool<_IsConst<_Src>::_Ret>::_Ret };
299  enum { _Is2 = _IsConvertible<_UnConstPtr<_Src>::_Type, _UnConstPtr<_Dst>::_Type>::value };
300  enum { value = _Is1 ? 0 : _Is2 };
301#  endif
302  typedef typename __bool2type<value>::_Ret _Ret;
303};
304
305#else
306template <class _Src, class _Dst>
307struct _IsConvertible {
308  enum { value = 0 };
309  typedef __false_type _Ret;
310};
311
312template <class _Src, class _Dst>
313struct _IsCVConvertible {
314  enum { value = 0 };
315  typedef __false_type _Ret;
316};
317#endif
318
319_STLP_END_NAMESPACE
320
321#endif /* _STLP_TYPE_MANIPS_H */
322