1/*
2 *
3 * Copyright (c) 1997
4 * Silicon Graphics Computer Systems, Inc.
5 *
6 * Permission to use, copy, modify, distribute and sell this software
7 * and its documentation for any purpose is hereby granted without fee,
8 * provided that the above copyright notice appear in all copies and
9 * that both that copyright notice and this permission notice appear
10 * in supporting documentation.  Silicon Graphics makes no
11 * representations about the suitability of this software for any
12 * purpose.  It is provided "as is" without express or implied warranty.
13 */
14
15#ifndef __TYPE_TRAITS_H
16#define __TYPE_TRAITS_H
17
18#ifndef __STL_CONFIG_H
19#include <stl_config.h>
20#endif
21
22/*
23This header file provides a framework for allowing compile time dispatch
24based on type attributes. This is useful when writing template code.
25For example, when making a copy of an array of an unknown type, it helps
26to know if the type has a trivial copy constructor or not, to help decide
27if a memcpy can be used.
28
29The class template __type_traits provides a series of typedefs each of
30which is either __true_type or __false_type. The argument to
31__type_traits can be any type. The typedefs within this template will
32attain their correct values by one of these means:
33    1. The general instantiation contain conservative values which work
34       for all types.
35    2. Specializations may be declared to make distinctions between types.
36    3. Some compilers (such as the Silicon Graphics N32 and N64 compilers)
37       will automatically provide the appropriate specializations for all
38       types.
39
40EXAMPLE:
41
42//Copy an array of elements which have non-trivial copy constructors
43template <class T> void copy(T* source, T* destination, int n, __false_type);
44//Copy an array of elements which have trivial copy constructors. Use memcpy.
45template <class T> void copy(T* source, T* destination, int n, __true_type);
46
47//Copy an array of any type by using the most efficient copy mechanism
48template <class T> inline void copy(T* source,T* destination,int n) {
49   copy(source, destination, n,
50        typename __type_traits<T>::has_trivial_copy_constructor());
51}
52*/
53
54
55struct __true_type {
56};
57
58struct __false_type {
59};
60
61template <class _Tp>
62struct __type_traits {
63   typedef __true_type     this_dummy_member_must_be_first;
64                   /* Do not remove this member. It informs a compiler which
65                      automatically specializes __type_traits that this
66                      __type_traits template is special. It just makes sure that
67                      things work if an implementation is using a template
68                      called __type_traits for something unrelated. */
69
70   /* The following restrictions should be observed for the sake of
71      compilers which automatically produce type specific specializations
72      of this class:
73          - You may reorder the members below if you wish
74          - You may remove any of the members below if you wish
75          - You must not rename members without making the corresponding
76            name change in the compiler
77          - Members you add will be treated like regular members unless
78            you add the appropriate support in the compiler. */
79
80
81   typedef __false_type    has_trivial_default_constructor;
82   typedef __false_type    has_trivial_copy_constructor;
83   typedef __false_type    has_trivial_assignment_operator;
84   typedef __false_type    has_trivial_destructor;
85   typedef __false_type    is_POD_type;
86};
87
88
89
90// Provide some specializations.  This is harmless for compilers that
91//  have built-in __types_traits support, and essential for compilers
92//  that don't.
93
94#ifndef __STL_NO_BOOL
95
96__STL_TEMPLATE_NULL struct __type_traits<bool> {
97   typedef __true_type    has_trivial_default_constructor;
98   typedef __true_type    has_trivial_copy_constructor;
99   typedef __true_type    has_trivial_assignment_operator;
100   typedef __true_type    has_trivial_destructor;
101   typedef __true_type    is_POD_type;
102};
103
104#endif /* __STL_NO_BOOL */
105
106__STL_TEMPLATE_NULL struct __type_traits<char> {
107   typedef __true_type    has_trivial_default_constructor;
108   typedef __true_type    has_trivial_copy_constructor;
109   typedef __true_type    has_trivial_assignment_operator;
110   typedef __true_type    has_trivial_destructor;
111   typedef __true_type    is_POD_type;
112};
113
114__STL_TEMPLATE_NULL struct __type_traits<signed char> {
115   typedef __true_type    has_trivial_default_constructor;
116   typedef __true_type    has_trivial_copy_constructor;
117   typedef __true_type    has_trivial_assignment_operator;
118   typedef __true_type    has_trivial_destructor;
119   typedef __true_type    is_POD_type;
120};
121
122__STL_TEMPLATE_NULL struct __type_traits<unsigned char> {
123   typedef __true_type    has_trivial_default_constructor;
124   typedef __true_type    has_trivial_copy_constructor;
125   typedef __true_type    has_trivial_assignment_operator;
126   typedef __true_type    has_trivial_destructor;
127   typedef __true_type    is_POD_type;
128};
129
130#ifdef __STL_HAS_WCHAR_T
131
132__STL_TEMPLATE_NULL struct __type_traits<wchar_t> {
133   typedef __true_type    has_trivial_default_constructor;
134   typedef __true_type    has_trivial_copy_constructor;
135   typedef __true_type    has_trivial_assignment_operator;
136   typedef __true_type    has_trivial_destructor;
137   typedef __true_type    is_POD_type;
138};
139
140#endif /* __STL_HAS_WCHAR_T */
141
142__STL_TEMPLATE_NULL struct __type_traits<short> {
143   typedef __true_type    has_trivial_default_constructor;
144   typedef __true_type    has_trivial_copy_constructor;
145   typedef __true_type    has_trivial_assignment_operator;
146   typedef __true_type    has_trivial_destructor;
147   typedef __true_type    is_POD_type;
148};
149
150__STL_TEMPLATE_NULL struct __type_traits<unsigned short> {
151   typedef __true_type    has_trivial_default_constructor;
152   typedef __true_type    has_trivial_copy_constructor;
153   typedef __true_type    has_trivial_assignment_operator;
154   typedef __true_type    has_trivial_destructor;
155   typedef __true_type    is_POD_type;
156};
157
158__STL_TEMPLATE_NULL struct __type_traits<int> {
159   typedef __true_type    has_trivial_default_constructor;
160   typedef __true_type    has_trivial_copy_constructor;
161   typedef __true_type    has_trivial_assignment_operator;
162   typedef __true_type    has_trivial_destructor;
163   typedef __true_type    is_POD_type;
164};
165
166__STL_TEMPLATE_NULL struct __type_traits<unsigned int> {
167   typedef __true_type    has_trivial_default_constructor;
168   typedef __true_type    has_trivial_copy_constructor;
169   typedef __true_type    has_trivial_assignment_operator;
170   typedef __true_type    has_trivial_destructor;
171   typedef __true_type    is_POD_type;
172};
173
174__STL_TEMPLATE_NULL struct __type_traits<long> {
175   typedef __true_type    has_trivial_default_constructor;
176   typedef __true_type    has_trivial_copy_constructor;
177   typedef __true_type    has_trivial_assignment_operator;
178   typedef __true_type    has_trivial_destructor;
179   typedef __true_type    is_POD_type;
180};
181
182__STL_TEMPLATE_NULL struct __type_traits<unsigned long> {
183   typedef __true_type    has_trivial_default_constructor;
184   typedef __true_type    has_trivial_copy_constructor;
185   typedef __true_type    has_trivial_assignment_operator;
186   typedef __true_type    has_trivial_destructor;
187   typedef __true_type    is_POD_type;
188};
189
190#ifdef __STL_LONG_LONG
191
192__STL_TEMPLATE_NULL struct __type_traits<long long> {
193   typedef __true_type    has_trivial_default_constructor;
194   typedef __true_type    has_trivial_copy_constructor;
195   typedef __true_type    has_trivial_assignment_operator;
196   typedef __true_type    has_trivial_destructor;
197   typedef __true_type    is_POD_type;
198};
199
200__STL_TEMPLATE_NULL struct __type_traits<unsigned long long> {
201   typedef __true_type    has_trivial_default_constructor;
202   typedef __true_type    has_trivial_copy_constructor;
203   typedef __true_type    has_trivial_assignment_operator;
204   typedef __true_type    has_trivial_destructor;
205   typedef __true_type    is_POD_type;
206};
207
208#endif /* __STL_LONG_LONG */
209
210__STL_TEMPLATE_NULL struct __type_traits<float> {
211   typedef __true_type    has_trivial_default_constructor;
212   typedef __true_type    has_trivial_copy_constructor;
213   typedef __true_type    has_trivial_assignment_operator;
214   typedef __true_type    has_trivial_destructor;
215   typedef __true_type    is_POD_type;
216};
217
218__STL_TEMPLATE_NULL struct __type_traits<double> {
219   typedef __true_type    has_trivial_default_constructor;
220   typedef __true_type    has_trivial_copy_constructor;
221   typedef __true_type    has_trivial_assignment_operator;
222   typedef __true_type    has_trivial_destructor;
223   typedef __true_type    is_POD_type;
224};
225
226__STL_TEMPLATE_NULL struct __type_traits<long double> {
227   typedef __true_type    has_trivial_default_constructor;
228   typedef __true_type    has_trivial_copy_constructor;
229   typedef __true_type    has_trivial_assignment_operator;
230   typedef __true_type    has_trivial_destructor;
231   typedef __true_type    is_POD_type;
232};
233
234#ifdef __STL_CLASS_PARTIAL_SPECIALIZATION
235
236template <class _Tp>
237struct __type_traits<_Tp*> {
238   typedef __true_type    has_trivial_default_constructor;
239   typedef __true_type    has_trivial_copy_constructor;
240   typedef __true_type    has_trivial_assignment_operator;
241   typedef __true_type    has_trivial_destructor;
242   typedef __true_type    is_POD_type;
243};
244
245#else /* __STL_CLASS_PARTIAL_SPECIALIZATION */
246
247__STL_TEMPLATE_NULL struct __type_traits<char*> {
248   typedef __true_type    has_trivial_default_constructor;
249   typedef __true_type    has_trivial_copy_constructor;
250   typedef __true_type    has_trivial_assignment_operator;
251   typedef __true_type    has_trivial_destructor;
252   typedef __true_type    is_POD_type;
253};
254
255__STL_TEMPLATE_NULL struct __type_traits<signed char*> {
256   typedef __true_type    has_trivial_default_constructor;
257   typedef __true_type    has_trivial_copy_constructor;
258   typedef __true_type    has_trivial_assignment_operator;
259   typedef __true_type    has_trivial_destructor;
260   typedef __true_type    is_POD_type;
261};
262
263__STL_TEMPLATE_NULL struct __type_traits<unsigned char*> {
264   typedef __true_type    has_trivial_default_constructor;
265   typedef __true_type    has_trivial_copy_constructor;
266   typedef __true_type    has_trivial_assignment_operator;
267   typedef __true_type    has_trivial_destructor;
268   typedef __true_type    is_POD_type;
269};
270
271__STL_TEMPLATE_NULL struct __type_traits<const char*> {
272   typedef __true_type    has_trivial_default_constructor;
273   typedef __true_type    has_trivial_copy_constructor;
274   typedef __true_type    has_trivial_assignment_operator;
275   typedef __true_type    has_trivial_destructor;
276   typedef __true_type    is_POD_type;
277};
278
279__STL_TEMPLATE_NULL struct __type_traits<const signed char*> {
280   typedef __true_type    has_trivial_default_constructor;
281   typedef __true_type    has_trivial_copy_constructor;
282   typedef __true_type    has_trivial_assignment_operator;
283   typedef __true_type    has_trivial_destructor;
284   typedef __true_type    is_POD_type;
285};
286
287__STL_TEMPLATE_NULL struct __type_traits<const unsigned char*> {
288   typedef __true_type    has_trivial_default_constructor;
289   typedef __true_type    has_trivial_copy_constructor;
290   typedef __true_type    has_trivial_assignment_operator;
291   typedef __true_type    has_trivial_destructor;
292   typedef __true_type    is_POD_type;
293};
294
295#endif /* __STL_CLASS_PARTIAL_SPECIALIZATION */
296
297
298// The following could be written in terms of numeric_limits.
299// We're doing it separately to reduce the number of dependencies.
300
301template <class _Tp> struct _Is_integer {
302  typedef __false_type _Integral;
303};
304
305#ifndef __STL_NO_BOOL
306
307__STL_TEMPLATE_NULL struct _Is_integer<bool> {
308  typedef __true_type _Integral;
309};
310
311#endif /* __STL_NO_BOOL */
312
313__STL_TEMPLATE_NULL struct _Is_integer<char> {
314  typedef __true_type _Integral;
315};
316
317__STL_TEMPLATE_NULL struct _Is_integer<signed char> {
318  typedef __true_type _Integral;
319};
320
321__STL_TEMPLATE_NULL struct _Is_integer<unsigned char> {
322  typedef __true_type _Integral;
323};
324
325#ifdef __STL_HAS_WCHAR_T
326
327__STL_TEMPLATE_NULL struct _Is_integer<wchar_t> {
328  typedef __true_type _Integral;
329};
330
331#endif /* __STL_HAS_WCHAR_T */
332
333__STL_TEMPLATE_NULL struct _Is_integer<short> {
334  typedef __true_type _Integral;
335};
336
337__STL_TEMPLATE_NULL struct _Is_integer<unsigned short> {
338  typedef __true_type _Integral;
339};
340
341__STL_TEMPLATE_NULL struct _Is_integer<int> {
342  typedef __true_type _Integral;
343};
344
345__STL_TEMPLATE_NULL struct _Is_integer<unsigned int> {
346  typedef __true_type _Integral;
347};
348
349__STL_TEMPLATE_NULL struct _Is_integer<long> {
350  typedef __true_type _Integral;
351};
352
353__STL_TEMPLATE_NULL struct _Is_integer<unsigned long> {
354  typedef __true_type _Integral;
355};
356
357#ifdef __STL_LONG_LONG
358
359__STL_TEMPLATE_NULL struct _Is_integer<long long> {
360  typedef __true_type _Integral;
361};
362
363__STL_TEMPLATE_NULL struct _Is_integer<unsigned long long> {
364  typedef __true_type _Integral;
365};
366
367#endif /* __STL_LONG_LONG */
368
369#endif /* __TYPE_TRAITS_H */
370
371// Local Variables:
372// mode:C++
373// End:
374