Re: [Boost-users] [shared_ptr] Is there an interface to set the ptr a

29 Dec 2008

      Sorry, this version is incorrect:

it should be

#define DECLARE_VAR_AUTO_CLEANER_BY_MEM_FN(CLASS, VAR, MEM_FN_CLEANER)\
	boost::shared_ptr<CLASS> auto__cleaner__for__ ## VAR\
		(&VAR, boost::bind(&CLASS::MEM_FN_CLEANER, _1));

#define DECLARE_PTR_AUTO_CLEANER_BY_MEM_FN(CLASS, VAR_PTR, MEM_FN_CLEANER)\
	boost::shared_ptr<CLASS> auto__cleaner__for ## VAR_PTR\
		(VAR_PTR,\
		boost::lambda::if_then(boost::lambda::_1!=static_cast<CLASS*>(0),\
		boost::lambda::bind(&CLASS::MEM_FN_CLEANER, boost::lambda::_1)))

// use case:

struct A
{
	void close() { delete this; }
};

{
	A *pa = new A();
	DECLARE_PTR_AUTO_CLEANER_BY_MEM_FN(A, pa, close);
}
// pa is cleaned by its close() function automatically

Max

=============================================================

Further, I've written the following macros for such use case:

#define DECLARE_VAR_PTR_WITH_AUTO_MEM_CLEANER(CLASS, VAR_PTR, MEM_FN_CLEANER)\
        CLASS *VAR_PTR;\
        boost::shared_ptr auto__cleaner__for__ ## VAR_PTR\
                (VAR_PTR, boost::bind(&CLASS::MEM_FN_CLEANER, _1));

#define DECLARE_VAR_WITH_AUTO_MEM_CLEANER(CLASS, VAR, MEM_FN_CLEANER)\
        CLASS VAR;\
        boost::shared_ptr auto__cleaner__for__ ## VAR\
                (&VAR, boost::bind(&CLASS::MEM_FN_CLEANER, _1));

Usage:

DECLARE_VAR_PTR_WITH_AUTO_MEM_CLEANER(AcDbBlockTable, pBlockTable, close);

Max

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