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/*
** ClanLib SDK
** Copyright (c) 1997-2005 The ClanLib Team
**
** This software is provided 'as-is', without any express or implied
** warranty. In no event will the authors be held liable for any damages
** arising from the use of this software.
**
** Permission is granted to anyone to use this software for any purpose,
** including commercial applications, and to alter it and redistribute it
** freely, subject to the following restrictions:
**
** 1. The origin of this software must not be misrepresented; you must not
** claim that you wrote the original software. If you use this software
** in a product, an acknowledgment in the product documentation would be
** appreciated but is not required.
** 2. Altered source versions must be plainly marked as such, and must not be
** misrepresented as being the original software.
** 3. This notice may not be removed or altered from any source distribution.
**
** Note: Some of the libraries ClanLib may link to may have additional
** requirements or restrictions.
**
** File Author(s):
**
** Magnus Norddahl
** (if your name is missing here, please add it)
*/
//! clanCore="System"
//! header=core.h
#ifndef clanlib_owningptr_header
#define clanlib_owningptr_header
//: Posessive pointer class (copying the pointer copies what it points to).
//- !group=Core/System!
//- !header=core.h!
//- <p> Use CL_OwningPtr when you require the data to be on the heap, but otherwise
//- want it to have very stack-instace-like semantics for copying, destruction, etc. </p>
template <typename T, typename U = T> class CL_OwningPtr
{
//! Construction:
public:
//: Constructs a CL_OwningPtr.
//param t: A pointer which was the return value of a 'new' call.
//- <p> After the CL_OwningPtr has been constructed based on a passed pointer,
//- the CL_OwningPtr takes full control over that data. The original pointer shouldn't
//- be used to access or delete the data anymore; instead, use the CL_OwningPtr. </p>
CL_OwningPtr() : ptr(0) {}
CL_OwningPtr(const CL_OwningPtr<T, U>& other) : ptr((T*)(other.ptr->clone())) {}
CL_OwningPtr(T* t) : ptr(t) {}
~CL_OwningPtr() {delete ptr;}
//! Attributes:
public:
//: Returns true if this CL_OwningPtr is not dereferencable.
bool is_null() const {if (ptr == 0) return true; return false;}
//: Gives access to the pointer itself.
//- <p> Be careful not to keep the returned pointer around after doing any
//- non-const operations on the CL_LazyCopyPtr; it could be invalid
//- after that.</p>
U* get() {return (U*)ptr;}
const U* get() const {return (const U*)ptr;}
//! Operations:
public:
//: Copy assignment operator.
//param t: A pointer which was the return value of a 'new' call.
//- <p> Once the assignment statement is finished when assigning a passed pointer,
//- the CL_OwningPtr takes full control over that data. The original pointer shouldn't
//- be used to access or delete the data anymore; instead, use the CL_OwningPtr. </p>
CL_OwningPtr<T, U>& operator=(const CL_OwningPtr<T, U>& other)
{
if (&other != this)
{
T* cpy;
if (other.ptr != 0)
cpy = (T*)(other.ptr->clone());
else
cpy = 0;
delete ptr;
ptr = cpy;
}
return *this;
}
CL_OwningPtr<T, U>& operator=(T* t)
{
delete ptr;
ptr = t;
return *this;
}
//: Dereferencing operator.
U& operator*() {return *((U*)ptr);}
U const& operator*() const {return *((const U*)ptr);}
//: Forces a const dereference.
//- <p> Like operator*, but forces a const deref even if in non-const context.
//- This is intended mostly to make it easy to exchange CL_OwningPtr and CL_LazyCopyPtr. </p>
U const& cd() const {return *((const U*)ptr);}
//: Indirect member access operator.
U* operator->() {return (U*)ptr;}
U const* operator->() const {return (const U*)ptr;}
//! Implementation:
private:
//Pointer to new-allocated data, or else 0
T* ptr;
//Not to be called, this just ensures that T is derived from CL_Clonable
void dummy() { ptr->must_be_derived_from_cl_clonable(); }
};
#endif
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