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#ifndef BASE_SCOPED_PTR_H
#define BASE_SCOPED_PTR_H
// (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
// Copyright (c) 2001, 2002 Peter Dimov
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
// See http://www.boost.org/libs/smart_ptr/scoped_ptr.htm for documentation.
//
// scoped_ptr mimics a built-in pointer except that it guarantees deletion
// of the object pointed to, either on destruction of the scoped_ptr or via
// an explicit reset(). scoped_ptr is a simple solution for simple needs;
// use shared_ptr or std::auto_ptr if your needs are more complex.
// *** NOTE ***
// If your scoped_ptr is a class member of class FOO pointing to a
// forward declared type BAR (as shown below), then you MUST use a non-inlined
// version of the destructor. The destructor of a scoped_ptr (called from
// FOO's destructor) must have a complete definition of BAR in order to
// destroy it. Example:
//
// -- foo.h --
// class BAR;
//
// class FOO {
// public:
// FOO();
// ~FOO(); // Required for sources that instantiate class FOO to compile!
//
// private:
// scoped_ptr<BAR> bar_;
// };
//
// -- foo.cc --
// #include "foo.h"
// FOO::~FOO() {} // Empty, but must be non-inlined to FOO's class definition.
#include <cstddef> // for std::ptrdiff_t
#include <assert.h> // for assert
#include <stdlib.h> // for free() decl
template <typename T>
class scoped_ptr {
private:
T* ptr;
scoped_ptr(scoped_ptr const &);
scoped_ptr & operator=(scoped_ptr const &);
public:
typedef T element_type;
explicit scoped_ptr(T* p = 0): ptr(p) {}
~scoped_ptr() {
typedef char type_must_be_complete[sizeof(T)];
delete ptr;
}
void reset(T* p = 0) {
typedef char type_must_be_complete[sizeof(T)];
if (ptr != p) {
delete ptr;
ptr = p;
}
}
T& operator*() const {
assert(ptr != 0);
return *ptr;
}
T* operator->() const {
assert(ptr != 0);
return ptr;
}
bool operator==(T* p) const {
return ptr == p;
}
bool operator!=(T* p) const {
return ptr != p;
}
T* get() const {
return ptr;
}
void swap(scoped_ptr & b) {
T* tmp = b.ptr;
b.ptr = ptr;
ptr = tmp;
}
T* release() {
T* tmp = ptr;
ptr = 0;
return tmp;
}
private:
// no reason to use these: each scoped_ptr should have its own object
template <typename U> bool operator==(scoped_ptr<U> const& p) const;
template <typename U> bool operator!=(scoped_ptr<U> const& p) const;
};
template<typename T> inline
void swap(scoped_ptr<T>& a, scoped_ptr<T>& b) {
a.swap(b);
}
template<typename T> inline
bool operator==(T* p, const scoped_ptr<T>& b) {
return p == b.get();
}
template<typename T> inline
bool operator!=(T* p, const scoped_ptr<T>& b) {
return p != b.get();
}
// scoped_array extends scoped_ptr to arrays. Deletion of the array pointed to
// is guaranteed, either on destruction of the scoped_array or via an explicit
// reset(). Use shared_array or std::vector if your needs are more complex.
template<typename T>
class scoped_array {
private:
T* ptr;
scoped_array(scoped_array const &);
scoped_array & operator=(scoped_array const &);
public:
typedef T element_type;
explicit scoped_array(T* p = 0) : ptr(p) {}
~scoped_array() {
typedef char type_must_be_complete[sizeof(T)];
delete[] ptr;
}
void reset(T* p = 0) {
typedef char type_must_be_complete[sizeof(T)];
if (ptr != p) {
delete [] ptr;
ptr = p;
}
}
T& operator[](std::ptrdiff_t i) const {
assert(ptr != 0);
assert(i >= 0);
return ptr[i];
}
bool operator==(T* p) const {
return ptr == p;
}
bool operator!=(T* p) const {
return ptr != p;
}
T* get() const {
return ptr;
}
void swap(scoped_array & b) {
T* tmp = b.ptr;
b.ptr = ptr;
ptr = tmp;
}
T* release() {
T* tmp = ptr;
ptr = 0;
return tmp;
}
private:
// no reason to use these: each scoped_array should have its own object
template <typename U> bool operator==(scoped_array<U> const& p) const;
template <typename U> bool operator!=(scoped_array<U> const& p) const;
};
template<class T> inline
void swap(::scoped_array<T>& a, ::scoped_array<T>& b) {
a.swap(b);
}
template<typename T> inline
bool operator==(T* p, const ::scoped_array<T>& b) {
return p == b.get();
}
template<typename T> inline
bool operator!=(T* p, const ::scoped_array<T>& b) {
return p != b.get();
}
// This class wraps the c library function free() in a class that can be
// passed as a template argument to scoped_ptr_malloc below.
class ScopedPtrMallocFree {
public:
inline void operator()(void* x) const {
free(x);
}
};
// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
// second template argument, the functor used to free the object.
template<typename T, typename FreeProc = ScopedPtrMallocFree>
class scoped_ptr_malloc {
private:
T* ptr;
scoped_ptr_malloc(scoped_ptr_malloc const &);
scoped_ptr_malloc & operator=(scoped_ptr_malloc const &);
public:
typedef T element_type;
explicit scoped_ptr_malloc(T* p = 0): ptr(p) {}
~scoped_ptr_malloc() {
typedef char type_must_be_complete[sizeof(T)];
free_((void*) ptr);
}
void reset(T* p = 0) {
typedef char type_must_be_complete[sizeof(T)];
if (ptr != p) {
free_((void*) ptr);
ptr = p;
}
}
T& operator*() const {
assert(ptr != 0);
return *ptr;
}
T* operator->() const {
assert(ptr != 0);
return ptr;
}
bool operator==(T* p) const {
return ptr == p;
}
bool operator!=(T* p) const {
return ptr != p;
}
T* get() const {
return ptr;
}
void swap(scoped_ptr_malloc & b) {
T* tmp = b.ptr;
b.ptr = ptr;
ptr = tmp;
}
T* release() {
T* tmp = ptr;
ptr = 0;
return tmp;
}
private:
// no reason to use these: each scoped_ptr_malloc should have its own object
template <typename U, typename GP>
bool operator==(scoped_ptr_malloc<U, GP> const& p) const;
template <typename U, typename GP>
bool operator!=(scoped_ptr_malloc<U, GP> const& p) const;
static FreeProc const free_;
};
template<typename T, typename FP>
FP const scoped_ptr_malloc<T,FP>::free_ = FP();
template<typename T, typename FP> inline
void swap(scoped_ptr_malloc<T,FP>& a, scoped_ptr_malloc<T,FP>& b) {
a.swap(b);
}
template<typename T, typename FP> inline
bool operator==(T* p, const scoped_ptr_malloc<T,FP>& b) {
return p == b.get();
}
template<typename T, typename FP> inline
bool operator!=(T* p, const scoped_ptr_malloc<T,FP>& b) {
return p != b.get();
}
#endif // #ifndef BASE_SCOPED_PTR_H