--- /dev/null
+#ifndef STLPLUS_SIMPLE_PTR\r
+#define STLPLUS_SIMPLE_PTR\r
+////////////////////////////////////////////////////////////////////////////////\r
+\r
+// Author: Daniel Milton, Andy Rushton\r
+// Copyright: (c) Southampton University 1999-2004\r
+// (c) Daniel Milton, Andy Rushton 2004-2009\r
+// License: BSD License, see ../docs/license.html\r
+\r
+// A smart pointer is a memory-managing pointer to an object. If you like, it\r
+// is a zero-dimensional container.\r
+\r
+// Assignment of smart pointers result in multiple aliases of the same object.\r
+// The term alias is used to differentiate from conventional pointers because\r
+// the semantics are different.\r
+\r
+// Aliases can be turned into copies if the pointed-to class supports copying.\r
+\r
+// These simple_ptr classes from DJDM have slightly different semantics than\r
+// the smart_ptr classes of AJR. There are no cross-pointer side effects\r
+// that occur when the pointer is cleared. The clear() function is effectively\r
+// equivalent to the clear_unique() function of the smart_ptr. The only way\r
+// that a "referenced" object will be deleted is if all simple_ptr's that\r
+// reference the object are cleared (by deletion, manual clearing or reassignment).\r
+\r
+// Also, the simple pointer cannot contain a reference to a shared null pointer\r
+// (which occurs as a side-effect of clearing a multiply referenced object in\r
+// the smart_ptr classes). Which means that if you have a null simple_ptr, then\r
+// the assignment of any other null simple_ptr will NOT reassign the reference of\r
+// any other simple_ptr. Hence, the simple_ptr class acts a little more like a\r
+// normal pointer (with fewer side effects), with the added bonus of containment.\r
+\r
+// Due to the way that the simple_ptr contains the data, it also allows the\r
+// addition of various casting functions, while still keeping the managed data\r
+// containment functionality of the underlying object. This means that you can\r
+// have two simple_ptr's of different template types, both pointing to the same\r
+// data (if the differing template types are derivatives of each other).\r
+\r
+// The base class is simple_ptr_base which defines the common interface. Then\r
+// there are three subclasses which have the same interface but different copy\r
+// semantics:\r
+\r
+// - simple_ptr for simple types and classes which have copy constructors\r
+// - simple_ptr_clone for polymorphic class hierarchies which are copied using a clone method\r
+// - simple_ptr_nocopy for any class that cannot or should not be copied\r
+\r
+////////////////////////////////////////////////////////////////////////////////\r
+#include "containers_fixes.hpp"\r
+#include "exceptions.hpp"\r
+#include "copy_functors.hpp"\r
+#include <map>\r
+#include <string>\r
+\r
+namespace stlplus\r
+{\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // Base class\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+\r
+ template<typename T, typename C>\r
+ class simple_ptr_base\r
+ {\r
+ public:\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // member type definitions\r
+\r
+ typedef T value_type;\r
+ typedef T& reference;\r
+ typedef const T& const_reference;\r
+ typedef C value_copy;\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // constructors and destructors\r
+\r
+ // create a null pointer\r
+ simple_ptr_base(void);\r
+\r
+ // create a pointer containing a *copy* of the object using the template parameter C\r
+ // this copy is taken because the pointer class maintains a dynamically allocated object\r
+ // and the T& may not be (usually is not) dynamically allocated\r
+ explicit simple_ptr_base(const T& data) throw(illegal_copy);\r
+\r
+ // create a pointer containing a dynamically created object\r
+ // Note: the object must be allocated *by the user* with new\r
+ // constructor form - must be called in the form smart_ptr_base<type> x(new type(args))\r
+ explicit simple_ptr_base(T* data);\r
+\r
+ // copy constructor implements aliasing so no copy is made\r
+ // note that the copy constructor should NOT be explicit, as this breaks\r
+ // the returning of pointer objects from functions (at least within GCC 4.4)\r
+ simple_ptr_base(const simple_ptr_base<T,C>& r);\r
+\r
+ // assignment operator - required, else the output of GCC suffers segmentation faults\r
+ simple_ptr_base<T,C>& operator=(const simple_ptr_base<T,C>& r);\r
+\r
+ // destructor decrements the reference count and delete only when the last reference is destroyed\r
+ ~simple_ptr_base(void);\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // logical tests to see if there is anything contained in the pointer since it can be null\r
+\r
+ // there are two forms:explicit and implicit\r
+ // implicit: if(!r) or if(r)\r
+ // explicit: if(r.null()) or if(r.present())\r
+ operator bool(void) const;\r
+ bool operator!(void) const;\r
+ bool present(void) const;\r
+ bool null(void) const;\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // dereference operators and functions\r
+\r
+ // dereference the smart pointer to get the object - use in the form *p1\r
+ T& operator*(void) throw(null_dereference);\r
+ const T& operator*(void) const throw(null_dereference);\r
+\r
+ // used as a prefix to a member access to the contained object e.g. p1->print() calls T::print()\r
+ T* operator->(void) throw(null_dereference);\r
+ const T* operator->(void) const throw(null_dereference);\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // explicit function forms of the above assignment and dereference operators\r
+\r
+ // set the value - note that this does a copy using the C template parameter\r
+ void set_value(const T& data) throw(illegal_copy);\r
+ // get the value\r
+ T& value(void) throw(null_dereference);\r
+ const T& value(void) const throw(null_dereference);\r
+\r
+ // set the pointer\r
+ // deletes the previous pointer and adopts the passed pointer instead\r
+ // Note: the object must be allocated *by the user* with new\r
+ // Warning: it is very easy to break the memory management with this operation\r
+ void set(T* data = 0);\r
+ // get the pointer\r
+ T* pointer(void);\r
+ const T* pointer(void) const;\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // functions to manage aliases\r
+\r
+ // make this an alias of the passed object\r
+ void alias(const simple_ptr_base<T,C>&);\r
+\r
+ // test whether two pointers point to the same object(known as aliasing the object)\r
+ // used in the form if(a.aliases(b))\r
+ bool aliases(const simple_ptr_base<T,C>&) const;\r
+\r
+ // find the number of aliases - used when you need to know whether an\r
+ // object is still referred to from elsewhere (rare!)\r
+ unsigned alias_count(void) const;\r
+\r
+ // clear the reference to the object, but only delete the object if there are no\r
+ // other references to that object. Hence, this does not affect other pointers\r
+ // that are pointing to the same object.\r
+ void clear(void);\r
+\r
+ // This is just an alias of the clear() function, provided for completeness of\r
+ // the interface when acting as a replacement for the smart_ptr classes\r
+ void clear_unique(void);\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // functions that involve copying\r
+\r
+ // these functions use the copy functor passed as the template parameter C\r
+ // to copy the object with the right copy semantics. If the copy functor\r
+ // is no_copy, an exception will be thrown.\r
+\r
+ // make this pointer unique with respect to any other references to the same object\r
+ // if this pointer is already unique, it does nothing - otherwise it copies the object\r
+ void make_unique(void) throw(illegal_copy);\r
+\r
+ // make this pointer a unique copy of the parameter\r
+ // useful for expressions like p1.copy(p2) which makes p1 a pointer to a unique copy of the contents of p2\r
+ void copy(const simple_ptr_base<T,C>&) throw(illegal_copy);\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+ // functions that involve casting\r
+\r
+#ifdef STLPLUS_MEMBER_TEMPLATES\r
+\r
+ // dynamic cast of underlying pointer to a derived/parent\r
+ template<typename T2> simple_ptr_base<T2,C> dyn_cast(void) const;\r
+\r
+ // static cast of underlying pointer to a derived/parent\r
+ template<typename T2> simple_ptr_base<T2,C> stat_cast(void) const;\r
+\r
+ // cast of underlying pointer to a base - while keeping the same ref-counted object\r
+ template<typename T2> simple_ptr_base<T2,C> cast(void) const;\r
+\r
+#endif\r
+\r
+ //////////////////////////////////////////////////////////////////////////////\r
+\r
+ protected:\r
+ T* m_pointer;\r
+ unsigned* m_count;\r
+\r
+ public:\r
+ // internal use only - had to make them public because they need to be\r
+ // accessed by routines that could not be made friends\r
+ // can't have a handle due to the way the simple pointer stores it's data\r
+ // in separate counter and pointer objects\r
+ unsigned* _count(void) const;\r
+ T* _pointer(void) const;\r
+ void _make_alias(T* pointer, unsigned* count);\r
+\r
+ private:\r
+ void increment(void);\r
+ bool decrement(void);\r
+ };\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // simple_ptr for simple types and classes which have copy constructors\r
+\r
+ template <typename T>\r
+ class simple_ptr : public simple_ptr_base<T, constructor_copy<T> >\r
+ {\r
+ public:\r
+ simple_ptr(void) {}\r
+ explicit simple_ptr(const T& data) : simple_ptr_base<T, constructor_copy<T> >(data) {}\r
+ explicit simple_ptr(T* data) : simple_ptr_base<T, constructor_copy<T> >(data) {}\r
+ simple_ptr<T>& operator=(const T& data) {set_value(data); return *this;}\r
+ simple_ptr<T>& operator=(T* data) {set(data); return *this;}\r
+ ~simple_ptr(void) {}\r
+ };\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // smart_ptr_clone for polymorphic class hierarchies which have a clone method\r
+\r
+ template <typename T>\r
+ class simple_ptr_clone : public simple_ptr_base<T, clone_copy<T> >\r
+ {\r
+ public:\r
+ simple_ptr_clone(void) {}\r
+ explicit simple_ptr_clone(const T& data) : simple_ptr_base<T, clone_copy<T> >(data) {}\r
+ explicit simple_ptr_clone(T* data) : simple_ptr_base<T, clone_copy<T> >(data) {}\r
+ simple_ptr_clone<T>& operator=(const T& data) {set_value(data); return *this;}\r
+ simple_ptr_clone<T>& operator=(T* data) {set(data); return *this;}\r
+ ~simple_ptr_clone(void) {}\r
+ };\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+ // smart_ptr_nocopy for any class that cannot or should not be copied\r
+\r
+ template <typename T>\r
+ class simple_ptr_nocopy : public simple_ptr_base<T, no_copy<T> >\r
+ {\r
+ public:\r
+ simple_ptr_nocopy(void) {}\r
+ explicit simple_ptr_nocopy(const T& data) : simple_ptr_base<T, no_copy<T> >(data) {}\r
+ explicit simple_ptr_nocopy(T* data) : simple_ptr_base<T, no_copy<T> >(data) {}\r
+ simple_ptr_nocopy<T>& operator=(const T& data) {set_value(data); return *this;}\r
+ simple_ptr_nocopy<T>& operator=(T* data) {set(data); return *this;}\r
+ ~simple_ptr_nocopy(void) {}\r
+ };\r
+\r
+ ////////////////////////////////////////////////////////////////////////////////\r
+\r
+} // end namespace stlplus\r
+\r
+#include "simple_ptr.tpp"\r
+#endif\r
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