shared_ptr_132.hpp 11.6 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478
#ifndef BOOST_SHARED_PTR_132_HPP_INCLUDED
#define BOOST_SHARED_PTR_132_HPP_INCLUDED

//
//  shared_ptr.hpp
//
//  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
//  Copyright (c) 2001, 2002, 2003 Peter Dimov
//
//  Distributed under the Boost Software License, Version 1.0. (See
//  accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//
//  See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
//

#include <boost/config.hpp>   // for broken compiler workarounds

#if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
#include <boost/serialization/detail/shared_ptr_nmt_132.hpp>
#else

#include <boost/assert.hpp>
#include <boost/checked_delete.hpp>
#include <boost/serialization/throw_exception.hpp>
#include <boost/detail/workaround.hpp>

#include <boost/serialization/access.hpp>
#include <boost/serialization/detail/shared_count_132.hpp>

#include <memory>               // for std::auto_ptr
#include <algorithm>            // for std::swap
#include <functional>           // for std::less
#include <typeinfo>             // for std::bad_cast
#include <iosfwd>               // for std::basic_ostream

#ifdef BOOST_MSVC  // moved here to work around VC++ compiler crash
# pragma warning(push)
# pragma warning(disable:4284) // odd return type for operator->
#endif

namespace boost_132 {

template<class T> class weak_ptr;
template<class T> class enable_shared_from_this;

namespace detail
{

struct static_cast_tag {};
struct const_cast_tag {};
struct dynamic_cast_tag {};
struct polymorphic_cast_tag {};

template<class T> struct shared_ptr_traits
{
    typedef T & reference;
};

template<> struct shared_ptr_traits<void>
{
    typedef void reference;
};

#if !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)

template<> struct shared_ptr_traits<void const>
{
    typedef void reference;
};

template<> struct shared_ptr_traits<void volatile>
{
    typedef void reference;
};

template<> struct shared_ptr_traits<void const volatile>
{
    typedef void reference;
};

#endif

// enable_shared_from_this support

template<class T, class Y> void sp_enable_shared_from_this( shared_count const & pn, enable_shared_from_this< T > const * pe, Y const * px )
{
    if(pe != 0) pe->_internal_weak_this._internal_assign(const_cast<Y*>(px), pn);
}

inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... )
{
}

} // namespace detail


//
//  shared_ptr
//
//  An enhanced relative of scoped_ptr with reference counted copy semantics.
//  The object pointed to is deleted when the last shared_ptr pointing to it
//  is destroyed or reset.
//

template<class T> class shared_ptr
{
private:
    // Borland 5.5.1 specific workaround
    typedef shared_ptr< T > this_type;

public:

    typedef T element_type;
    typedef T value_type;
    typedef T * pointer;
    typedef BOOST_DEDUCED_TYPENAME detail::shared_ptr_traits< T >::reference reference;

    shared_ptr(): px(0), pn() // never throws in 1.30+
    {
    }

#if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT( 0x564) )
    template<class Y>
    explicit shared_ptr(Y * p): px(p), pn(p, boost::checked_deleter<Y>()) // Y must be complete
#else
    template<class Y>
    explicit shared_ptr(Y * p): px(p), pn(p, boost::checked_deleter<Y>()) // Y must be complete
#endif
    {
        detail::sp_enable_shared_from_this( pn, p, p );
    }

    //
    // Requirements: D's copy constructor must not throw
    //
    // shared_ptr will release p by calling d(p)
    //

    template<class Y, class D> shared_ptr(Y * p, D d): px(p), pn(p, d)
    {
        detail::sp_enable_shared_from_this( pn, p, p );
    }

//  generated copy constructor, assignment, destructor are fine...

//  except that Borland C++ has a bug, and g++ with -Wsynth warns
#if defined(__BORLANDC__) || defined(__GNUC__)

    shared_ptr & operator=(shared_ptr const & r) // never throws
    {
        px = r.px;
        pn = r.pn; // shared_count::op= doesn't throw
        return *this;
    }

#endif

    template<class Y>
    explicit shared_ptr(weak_ptr<Y> const & r): pn(r.pn) // may throw
    {
        // it is now safe to copy r.px, as pn(r.pn) did not throw
        px = r.px;
    }

    template<class Y>
    shared_ptr(shared_ptr<Y> const & r): px(r.px), pn(r.pn) // never throws
    {
    }

    template<class Y>
    shared_ptr(shared_ptr<Y> const & r, detail::static_cast_tag): px(static_cast<element_type *>(r.px)), pn(r.pn)
    {
    }

    template<class Y>
    shared_ptr(shared_ptr<Y> const & r, detail::const_cast_tag): px(const_cast<element_type *>(r.px)), pn(r.pn)
    {
    }

    template<class Y>
    shared_ptr(shared_ptr<Y> const & r, detail::dynamic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
    {
        if(px == 0) // need to allocate new counter -- the cast failed
        {
            pn = detail::shared_count();
        }
    }

    template<class Y>
    shared_ptr(shared_ptr<Y> const & r, detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)
    {
        if(px == 0)
        {
            boost::serialization::throw_exception(std::bad_cast());
        }
    }

#ifndef BOOST_NO_AUTO_PTR

    template<class Y>
    explicit shared_ptr(std::auto_ptr<Y> & r): px(r.get()), pn()
    {
        Y * tmp = r.get();
        pn = detail::shared_count(r);
        detail::sp_enable_shared_from_this( pn, tmp, tmp );
    }

#endif

#if !defined(BOOST_MSVC) || (BOOST_MSVC > 1200)

    template<class Y>
    shared_ptr & operator=(shared_ptr<Y> const & r) // never throws
    {
        px = r.px;
        pn = r.pn; // shared_count::op= doesn't throw
        return *this;
    }

#endif

#ifndef BOOST_NO_AUTO_PTR

    template<class Y>
    shared_ptr & operator=(std::auto_ptr<Y> & r)
    {
        this_type(r).swap(*this);
        return *this;
    }

#endif

    void reset() // never throws in 1.30+
    {
        this_type().swap(*this);
    }

    template<class Y> void reset(Y * p) // Y must be complete
    {
        BOOST_ASSERT(p == 0 || p != px); // catch self-reset errors
        this_type(p).swap(*this);
    }

    template<class Y, class D> void reset(Y * p, D d)
    {
        this_type(p, d).swap(*this);
    }

    reference operator* () const // never throws
    {
        BOOST_ASSERT(px != 0);
        return *px;
    }

    T * operator-> () const // never throws
    {
        BOOST_ASSERT(px != 0);
        return px;
    }
    
    T * get() const // never throws
    {
        return px;
    }

    // implicit conversion to "bool"

#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)

    operator bool () const
    {
        return px != 0;
    }

#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
    typedef T * (this_type::*unspecified_bool_type)() const;
    
    operator unspecified_bool_type() const // never throws
    {
        return px == 0? 0: &this_type::get;
    }

#else 

    typedef T * this_type::*unspecified_bool_type;

    operator unspecified_bool_type() const // never throws
    {
        return px == 0? 0: &this_type::px;
    }

#endif

    // operator! is redundant, but some compilers need it

    bool operator! () const // never throws
    {
        return px == 0;
    }

    bool unique() const // never throws
    {
        return pn.unique();
    }

    long use_count() const // never throws
    {
        return pn.use_count();
    }

    void swap(shared_ptr< T > & other) // never throws
    {
        std::swap(px, other.px);
        pn.swap(other.pn);
    }

    template<class Y> bool _internal_less(shared_ptr<Y> const & rhs) const
    {
        return pn < rhs.pn;
    }

    void * _internal_get_deleter(std::type_info const & ti) const
    {
        return pn.get_deleter(ti);
    }

// Tasteless as this may seem, making all members public allows member templates
// to work in the absence of member template friends. (Matthew Langston)

#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS

private:

    template<class Y> friend class shared_ptr;
    template<class Y> friend class weak_ptr;


#endif
public: // for serialization
    T * px;                     // contained pointer
    detail::shared_count pn;    // reference counter

};  // shared_ptr

template<class T, class U> inline bool operator==(shared_ptr< T > const & a, shared_ptr<U> const & b)
{
    return a.get() == b.get();
}

template<class T, class U> inline bool operator!=(shared_ptr< T > const & a, shared_ptr<U> const & b)
{
    return a.get() != b.get();
}

#if __GNUC__ == 2 && __GNUC_MINOR__ <= 96

// Resolve the ambiguity between our op!= and the one in rel_ops

template<class T> inline bool operator!=(shared_ptr< T > const & a, shared_ptr< T > const & b)
{
    return a.get() != b.get();
}

#endif

template<class T, class U> inline bool operator<(shared_ptr< T > const & a, shared_ptr<U> const & b)
{
    return a._internal_less(b);
}

template<class T> inline void swap(shared_ptr< T > & a, shared_ptr< T > & b)
{
    a.swap(b);
}

template<class T, class U> shared_ptr< T > static_pointer_cast(shared_ptr<U> const & r)
{
    return shared_ptr< T >(r, detail::static_cast_tag());
}

template<class T, class U> shared_ptr< T > const_pointer_cast(shared_ptr<U> const & r)
{
    return shared_ptr< T >(r, detail::const_cast_tag());
}

template<class T, class U> shared_ptr< T > dynamic_pointer_cast(shared_ptr<U> const & r)
{
    return shared_ptr< T >(r, detail::dynamic_cast_tag());
}

// shared_*_cast names are deprecated. Use *_pointer_cast instead.

template<class T, class U> shared_ptr< T > shared_static_cast(shared_ptr<U> const & r)
{
    return shared_ptr< T >(r, detail::static_cast_tag());
}

template<class T, class U> shared_ptr< T > shared_dynamic_cast(shared_ptr<U> const & r)
{
    return shared_ptr< T >(r, detail::dynamic_cast_tag());
}

template<class T, class U> shared_ptr< T > shared_polymorphic_cast(shared_ptr<U> const & r)
{
    return shared_ptr< T >(r, detail::polymorphic_cast_tag());
}

template<class T, class U> shared_ptr< T > shared_polymorphic_downcast(shared_ptr<U> const & r)
{
    BOOST_ASSERT(dynamic_cast<T *>(r.get()) == r.get());
    return shared_static_cast< T >(r);
}

// get_pointer() enables boost::mem_fn to recognize shared_ptr

template<class T> inline T * get_pointer(shared_ptr< T > const & p)
{
    return p.get();
}

// operator<<

#if defined(__GNUC__) &&  (__GNUC__ < 3)

template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)
{
    os << p.get();
    return os;
}

#else

# if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, <= 1200 && __SGI_STL_PORT)
// MSVC6 has problems finding std::basic_ostream through the using declaration in namespace _STL
using std::basic_ostream;
template<class E, class T, class Y> basic_ostream<E, T> & operator<< (basic_ostream<E, T> & os, shared_ptr<Y> const & p)
# else
template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::basic_ostream<E, T> & os, shared_ptr<Y> const & p)
# endif 
{
    os << p.get();
    return os;
}

#endif

// get_deleter (experimental)

#if (defined(__GNUC__) &&  (__GNUC__ < 3)) || (defined(__EDG_VERSION__) && (__EDG_VERSION__ <= 238))

// g++ 2.9x doesn't allow static_cast<X const *>(void *)
// apparently EDG 2.38 also doesn't accept it

template<class D, class T> D * get_deleter(shared_ptr< T > const & p)
{
    void const * q = p._internal_get_deleter(typeid(D));
    return const_cast<D *>(static_cast<D const *>(q));
}

#else

template<class D, class T> D * get_deleter(shared_ptr< T > const & p)
{
    return static_cast<D *>(p._internal_get_deleter(typeid(D)));
}

#endif

} // namespace boost

#ifdef BOOST_MSVC
# pragma warning(pop)
#endif    

#endif  // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)

#endif  // #ifndef BOOST_SHARED_PTR_132_HPP_INCLUDED