coco
142 lines
4.1 KiB
C++
142 lines
4.1 KiB
C++
// Copyright (C) 2003 Davis E. King (davis@dlib.net)
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// License: Boost Software License See LICENSE.txt for the full license.
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#undef DLIB_REFERENCE_COUNTER_KERNEl_ABSTRACT_
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#ifdef DLIB_REFERENCE_COUNTER_KERNEl_ABSTRACT_
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#include "../algs.h"
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namespace dlib
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{
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template <
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typename T,
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typename copy = copy_functor<T>
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>
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class reference_counter
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{
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/*!
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REQUIREMENTS ON T
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T must have a default constructor
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REQUIREMENTS ON copy
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it should be a function object that copies an object of type T. and
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it must have a default constructor and
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operator() should be overloaded as
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void operator()(const T& source, T& destination);
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copy may throw any exception
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POINTERS AND REFERENCES TO INTERNAL DATA
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swap() and access() functions do not invalidate pointers or
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references to internal data.
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All other functions have no such guarantee
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INITIAL VALUE
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reference_counter contains one object of type T and
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this object of type T has its initial value
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WHAT THIS OBJECT REPRESENTS
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This object represents a container for an object of type T and
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provides reference counting capabilities for the object it contains
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Also note that unless specified otherwise, no member functions
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of this object throw exceptions.
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!*/
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public:
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typedef T type;
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reference_counter (
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);
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/*!
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ensures
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- #*this is properly initialized
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throws
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- std::bad_alloc or any exception thrown by T's constructor
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!*/
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reference_counter (
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const reference_counter& item
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);
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/*!
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ensures
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- #access() == item.access()
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!*/
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virtual ~reference_counter (
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);
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/*!
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ensures
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- all memory associated with *this has been released
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!*/
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void clear (
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);
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/*!
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ensures
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- #*this has its initial value
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throws
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- std::bad_alloc or any exception thrown by T's constructor
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if this exception is thrown then *this is unusable
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until clear() is called and succeeds
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!*/
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T& modify (
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);
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/*!
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ensures
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- returns a non-const reference to the item contained in *this
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- the item is ok to modify. i.e. there are no other references to it
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throws
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- std::bad_alloc or any exception thrown by T's constructor
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modify() may throw this exception if there are other references
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to the item and there is not enough memory to copy it. If modify()
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throws then it has no effect.
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!*/
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const T& access (
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) const;
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/*!
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ensures
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- returns a const reference to the item contained in *this
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- there may be other references to to the item
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!*/
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reference_counter& operator= (
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const reference_counter& rhs
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);
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/*!
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ensures
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- #access() == rhs.access()
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!*/
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void swap (
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reference_counter& item
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);
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/*!
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ensures
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- swaps *this and item
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!*/
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};
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template <
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typename T,
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typename copy
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>
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inline void swap (
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reference_counter<T,copy>& a,
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reference_counter<T,copy>& b
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) { a.swap(b); }
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/*!
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provides a global swap function
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!*/
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}
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#endif // DLIB_REFERENCE_COUNTER_KERNEl_ABSTRACT_
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