1 // Baruch Even baruch@ev-en.org 2001-02-20
2 // This version is a modified version for use in LyX
3 // The modifications are done in order to use it where exceptions are disabled
4 // Currently it has no "no memory" checks in place, asserts are probably the
6 // all changed are #ifded'ed by LYX_NO_EXCEPTIONS
7 #define LYX_NO_EXCEPTIONS
9 // Boost smart_ptr.hpp header file -----------------------------------------//
11 // (C) Copyright Greg Colvin and Beman Dawes 1998, 1999. Permission to copy,
12 // use, modify, sell and distribute this software is granted provided this
13 // copyright notice appears in all copies. This software is provided "as is"
14 // without express or implied warranty, and with no claim as to its
15 // suitability for any purpose.
17 // See http://www.boost.org for most recent version including documentation.
20 // 21 May 01 Require complete type where incomplete type is unsafe.
21 // (suggested by Vladimir Prus)
22 // 21 May 01 operator= fails if operand transitively owned by *this, as in a
23 // linked list (report by Ken Johnson, fix by Beman Dawes)
24 // 21 Jan 01 Suppress some useless warnings with MSVC (David Abrahams)
25 // 19 Oct 00 Make shared_ptr ctor from auto_ptr explicit. (Robert Vugts)
26 // 24 Jul 00 Change throw() to // never throws. See lib guidelines
27 // Exception-specification rationale. (Beman Dawes)
28 // 22 Jun 00 Remove #if continuations to fix GCC 2.95.2 problem (Beman Dawes)
29 // 1 Feb 00 Additional shared_ptr BOOST_NO_MEMBER_TEMPLATES workarounds
31 // 31 Dec 99 Condition tightened for no member template friend workaround
33 // 30 Dec 99 Moved BOOST_NMEMBER_TEMPLATES compatibility code to config.hpp
35 // 30 Nov 99 added operator ==, operator !=, and std::swap and std::less
36 // specializations for shared types (Darin Adler)
37 // 11 Oct 99 replaced op[](int) with op[](std::size_t) (Ed Brey, Valentin
38 // Bonnard), added shared_ptr workaround for no member template
39 // friends (Matthew Langston)
40 // 25 Sep 99 added shared_ptr::swap and shared_array::swap (Luis Coelho).
41 // 20 Jul 99 changed name to smart_ptr.hpp, #include <boost/config.hpp>,
42 // #include <boost/utility.hpp> and use boost::noncopyable
43 // 17 May 99 remove scoped_array and shared_array operator*() as
44 // unnecessary (Beman Dawes)
45 // 14 May 99 reorder code so no effects when bad_alloc thrown (Abrahams/Dawes)
46 // 13 May 99 remove certain throw() specifiers to avoid generated try/catch
47 // code cost (Beman Dawes)
48 // 11 May 99 get() added, conversion to T* placed in macro guard (Valentin
49 // Bonnard, Dave Abrahams, and others argued for elimination
50 // of the automatic conversion)
51 // 28 Apr 99 #include <memory> fix (Valentin Bonnard)
52 // 28 Apr 99 rename transfer() to share() for clarity (Dave Abrahams)
53 // 28 Apr 99 remove unsafe shared_array template conversions(Valentin Bonnard)
54 // 28 Apr 99 p(r) changed to p(r.px) for clarity (Dave Abrahams)
55 // 21 Apr 99 reset() self assignment fix (Valentin Bonnard)
56 // 21 Apr 99 dispose() provided to improve clarity (Valentin Bonnard)
57 // 27 Apr 99 leak when new throws fixes (Dave Abrahams)
58 // 21 Oct 98 initial Version (Greg Colvin/Beman Dawes)
60 #ifndef BOOST_SMART_PTR_HPP
61 #define BOOST_SMART_PTR_HPP
63 #include <boost/config.hpp> // for broken compiler workarounds
64 #include <cstddef> // for std::size_t
65 #include <memory> // for std::auto_ptr
66 #include <algorithm> // for std::swap
67 #include <boost/utility.hpp> // for boost::noncopyable, checked_delete, checked_array_delete
68 #include <functional> // for std::less
69 #include <boost/static_assert.hpp> // for BOOST_STATIC_ASSERT
71 #ifdef LYX_NO_EXCEPTIONS
75 #ifdef BOOST_MSVC // moved here to work around VC++ compiler crash
76 # pragma warning(push)
77 # pragma warning(disable:4284) // return type for 'identifier::operator->' is not a UDT or reference to a UDT. Will produce errors if applied using infix notation
82 // scoped_ptr --------------------------------------------------------------//
84 // scoped_ptr mimics a built-in pointer except that it guarantees deletion
85 // of the object pointed to, either on destruction of the scoped_ptr or via
86 // an explicit reset(). scoped_ptr is a simple solution for simple needs;
87 // see shared_ptr (below) or std::auto_ptr if your needs are more complex.
89 template<typename T> class scoped_ptr : noncopyable {
94 typedef T element_type;
96 explicit scoped_ptr( T* p=0 ) : ptr(p) {} // never throws
97 ~scoped_ptr() { checked_delete(ptr); }
98 void reset( T* p=0 ) { if ( ptr != p ) { checked_delete(ptr); ptr = p; } }
99 T& operator*() const { return *ptr; } // never throws
100 T* operator->() const { return ptr; } // never throws
101 T* get() const { return ptr; } // never throws
102 #ifdef BOOST_SMART_PTR_CONVERSION
103 // get() is safer! Define BOOST_SMART_PTR_CONVERSION at your own risk!
104 operator T*() const { return ptr; } // never throws
108 // scoped_array ------------------------------------------------------------//
110 // scoped_array extends scoped_ptr to arrays. Deletion of the array pointed to
111 // is guaranteed, either on destruction of the scoped_array or via an explicit
112 // reset(). See shared_array or std::vector if your needs are more complex.
114 template<typename T> class scoped_array : noncopyable {
119 typedef T element_type;
121 explicit scoped_array( T* p=0 ) : ptr(p) {} // never throws
122 ~scoped_array() { checked_array_delete(ptr); }
124 void reset( T* p=0 ) { if ( ptr != p )
125 {checked_array_delete(ptr); ptr=p;} }
127 T* get() const { return ptr; } // never throws
128 #ifdef BOOST_SMART_PTR_CONVERSION
129 // get() is safer! Define BOOST_SMART_PTR_CONVERSION at your own risk!
130 operator T*() const { return ptr; } // never throws
132 T& operator[](std::size_t i) const { return ptr[i]; } // never throws
136 // shared_ptr --------------------------------------------------------------//
138 // An enhanced relative of scoped_ptr with reference counted copy semantics.
139 // The object pointed to is deleted when the last shared_ptr pointing to it
140 // is destroyed or reset.
142 template<typename T> class shared_ptr {
144 typedef T element_type;
146 explicit shared_ptr(T* p =0) : px(p) {
147 #ifndef LYX_NO_EXCEPTIONS
148 try { pn = new long(1); } // fix: prevent leak if new throws
149 catch (...) { checked_delete(p); throw; }
156 shared_ptr(const shared_ptr& r) : px(r.px) { ++*(pn = r.pn); } // never throws
158 ~shared_ptr() { dispose(); }
160 shared_ptr& operator=(const shared_ptr& r) {
165 #if !defined( BOOST_NO_MEMBER_TEMPLATES )
167 shared_ptr(const shared_ptr<Y>& r) : px(r.px) { // never throws
170 #ifndef BOOST_NO_AUTO_PTR
172 explicit shared_ptr(std::auto_ptr<Y>& r) {
173 pn = new long(1); // may throw
174 px = r.release(); // fix: moved here to stop leak if new throws
179 shared_ptr& operator=(const shared_ptr<Y>& r) {
184 #ifndef BOOST_NO_AUTO_PTR
186 shared_ptr& operator=(std::auto_ptr<Y>& r) {
187 // code choice driven by guarantee of "no effect if new throws"
188 if (*pn == 1) { checked_delete(px); }
189 else { // allocate new reference counter
190 long * tmp = new long(1); // may throw
191 --*pn; // only decrement once danger of new throwing is past
193 } // allocate new reference counter
194 px = r.release(); // fix: moved here so doesn't leak if new throws
199 #ifndef BOOST_NO_AUTO_PTR
200 explicit shared_ptr(std::auto_ptr<T>& r) {
201 pn = new long(1); // may throw
202 px = r.release(); // fix: moved here to stop leak if new throws
205 shared_ptr& operator=(std::auto_ptr<T>& r) {
206 // code choice driven by guarantee of "no effect if new throws"
207 if (*pn == 1) { checked_delete(px); }
208 else { // allocate new reference counter
209 long * tmp = new long(1); // may throw
210 --*pn; // only decrement once danger of new throwing is past
212 } // allocate new reference counter
213 px = r.release(); // fix: moved here so doesn't leak if new throws
220 if ( px == p ) return; // fix: self-assignment safe
221 if (--*pn == 0) { checked_delete(px); }
222 else { // allocate new reference counter
223 #ifndef LYX_NO_EXCEPTIONS
224 try { pn = new long; } // fix: prevent leak if new throws
226 ++*pn; // undo effect of --*pn above to meet effects guarantee
234 } // allocate new reference counter
239 T& operator*() const { return *px; } // never throws
240 T* operator->() const { return px; } // never throws
241 T* get() const { return px; } // never throws
242 #ifdef BOOST_SMART_PTR_CONVERSION
243 // get() is safer! Define BOOST_SMART_PTR_CONVERSION at your own risk!
244 operator T*() const { return px; } // never throws
247 long use_count() const { return *pn; } // never throws
248 bool unique() const { return *pn == 1; } // never throws
250 void swap(shared_ptr<T>& other) // never throws
251 { std::swap(px,other.px); std::swap(pn,other.pn); }
253 // Tasteless as this may seem, making all members public allows member templates
254 // to work in the absence of member template friends. (Matthew Langston)
255 // Don't split this line into two; that causes problems for some GCC 2.95.2 builds
256 #if defined(BOOST_NO_MEMBER_TEMPLATES) || !defined( BOOST_NO_MEMBER_TEMPLATE_FRIENDS )
260 T* px; // contained pointer
261 long* pn; // ptr to reference counter
263 // Don't split this line into two; that causes problems for some GCC 2.95.2 builds
264 #if !defined( BOOST_NO_MEMBER_TEMPLATES ) && !defined( BOOST_NO_MEMBER_TEMPLATE_FRIENDS )
265 template<typename Y> friend class shared_ptr;
268 void dispose() { if (--*pn == 0) { checked_delete(px); delete pn; } }
270 void share(T* rpx, long* rpn) {
271 if (pn != rpn) { // Q: why not px != rpx? A: fails when both == 0
272 ++*rpn; // done before dispose() in case rpn transitively
273 // dependent on *this (bug reported by Ken Johnson)
281 template<typename T, typename U>
282 inline bool operator==(const shared_ptr<T>& a, const shared_ptr<U>& b)
283 { return a.get() == b.get(); }
285 template<typename T, typename U>
286 inline bool operator!=(const shared_ptr<T>& a, const shared_ptr<U>& b)
287 { return a.get() != b.get(); }
289 // shared_array ------------------------------------------------------------//
291 // shared_array extends shared_ptr to arrays.
292 // The array pointed to is deleted when the last shared_array pointing to it
293 // is destroyed or reset.
295 template<typename T> class shared_array {
297 typedef T element_type;
299 explicit shared_array(T* p =0) : px(p) {
300 #ifndef LYX_NO_EXCEPTIONS
301 try { pn = new long(1); } // fix: prevent leak if new throws
302 catch (...) { checked_array_delete(p); throw; }
309 shared_array(const shared_array& r) : px(r.px) // never throws
312 ~shared_array() { dispose(); }
314 shared_array& operator=(const shared_array& r) {
315 if (pn != r.pn) { // Q: why not px != r.px? A: fails when both px == 0
316 ++*r.pn; // done before dispose() in case r.pn transitively
317 // dependent on *this (bug reported by Ken Johnson)
326 if ( px == p ) return; // fix: self-assignment safe
327 if (--*pn == 0) { checked_array_delete(px); }
328 else { // allocate new reference counter
329 #ifndef LYX_NO_EXCEPTIONS
330 try { pn = new long; } // fix: prevent leak if new throws
332 ++*pn; // undo effect of --*pn above to meet effects guarantee
333 checked_array_delete(p);
340 } // allocate new reference counter
345 T* get() const { return px; } // never throws
346 #ifdef BOOST_SMART_PTR_CONVERSION
347 // get() is safer! Define BOOST_SMART_PTR_CONVERSION at your own risk!
348 operator T*() const { return px; } // never throws
350 T& operator[](std::size_t i) const { return px[i]; } // never throws
353 long use_count() const { return *pn; } // never throws
354 bool unique() const { return *pn == 1; } // never throws
356 void swap(shared_array<T>& other) // never throws
357 { std::swap(px,other.px); std::swap(pn,other.pn); }
361 T* px; // contained pointer
362 long* pn; // ptr to reference counter
364 void dispose() { if (--*pn == 0) { checked_array_delete(px); delete pn; } }
369 inline bool operator==(const shared_array<T>& a, const shared_array<T>& b)
370 { return a.get() == b.get(); }
373 inline bool operator!=(const shared_array<T>& a, const shared_array<T>& b)
374 { return a.get() != b.get(); }
378 // specializations for things in namespace std -----------------------------//
380 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
384 // Specialize std::swap to use the fast, non-throwing swap that's provided
385 // as a member function instead of using the default algorithm which creates
386 // a temporary and uses assignment.
389 inline void swap(boost::shared_ptr<T>& a, boost::shared_ptr<T>& b)
393 inline void swap(boost::shared_array<T>& a, boost::shared_array<T>& b)
396 // Specialize std::less so we can use shared pointers and arrays as keys in
397 // associative collections.
399 // It's still a controversial question whether this is better than supplying
400 // a full range of comparison operators (<, >, <=, >=).
403 struct less< boost::shared_ptr<T> >
404 : binary_function<boost::shared_ptr<T>, boost::shared_ptr<T>, bool>
406 bool operator()(const boost::shared_ptr<T>& a,
407 const boost::shared_ptr<T>& b) const
408 { return less<T*>()(a.get(),b.get()); }
412 struct less< boost::shared_array<T> >
413 : binary_function<boost::shared_array<T>, boost::shared_array<T>, bool>
415 bool operator()(const boost::shared_array<T>& a,
416 const boost::shared_array<T>& b) const
417 { return less<T*>()(a.get(),b.get()); }
422 #endif // ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
428 #endif // BOOST_SMART_PTR_HPP