64 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			64 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| // Copyright David Abrahams 2002.
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| // Distributed under the Boost Software License, Version 1.0. (See
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| // accompanying file LICENSE_1_0.txt or copy at
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| // http://www.boost.org/LICENSE_1_0.txt)
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| #ifndef INSTANCE_HOLDER_DWA2002517_HPP
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| # define INSTANCE_HOLDER_DWA2002517_HPP
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| 
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| # include <boost/python/detail/prefix.hpp>
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| 
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| # include <boost/noncopyable.hpp>
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| # include <boost/python/type_id.hpp>
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| # include <cstddef>
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| 
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| namespace boost { namespace python { 
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| 
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| // Base class for all holders
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| struct BOOST_PYTHON_DECL instance_holder : private noncopyable
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| {
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|  public:
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|     instance_holder();
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|     virtual ~instance_holder();
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|     
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|     // return the next holder in a chain
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|     instance_holder* next() const;
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| 
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|     // When the derived holder actually holds by [smart] pointer and
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|     // null_ptr_only is set, only report that the type is held when
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|     // the pointer is null.  This is needed for proper shared_ptr
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|     // support, to prevent holding shared_ptrs from being found when
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|     // converting from python so that we can use the conversion method
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|     // that always holds the Python object.
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|     virtual void* holds(type_info, bool null_ptr_only) = 0;
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| 
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|     void install(PyObject* inst) throw();
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| 
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|     // These functions should probably be located elsewhere.
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|     
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|     // Allocate storage for an object of the given size at the given
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|     // offset in the Python instance<> object if bytes are available
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|     // there. Otherwise allocate size bytes of heap memory.
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|     static void* allocate(PyObject*, std::size_t offset, std::size_t size);
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| 
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|     // Deallocate storage from the heap if it was not carved out of
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|     // the given Python object by allocate(), above.
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|     static void deallocate(PyObject*, void* storage) throw();
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|  private:
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|     instance_holder* m_next;
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| };
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| 
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| // This macro is needed for implementation of derived holders
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| # define BOOST_PYTHON_UNFORWARD(N,ignored) (typename unforward<A##N>::type)(a##N)
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| 
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| //
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| // implementation
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| //
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| inline instance_holder* instance_holder::next() const
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| {
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|     return m_next;
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| }
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| 
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| }} // namespace boost::python
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| 
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| #endif // INSTANCE_HOLDER_DWA2002517_HPP
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