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82 lines
1.3 KiB
82 lines
1.3 KiB
#pragma once
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//////////////////////////////////////////////////////////////////////////////////////////
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//////////////////////////////////////////////////////////////////////////////////////////
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// auto_pv- auto PROPVARIANT releaser.
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//
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// pretty minimal functionality, designed to provide auto release only
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//
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class auto_pv : public ::tagPROPVARIANT {
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public:
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// Constructors
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//
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auto_pv() throw();
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// Destructor
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//
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~auto_pv() throw();
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// Low-level operations
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//
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void Clear() throw();
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void Attach(PROPVARIANT& varSrc) throw();
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PROPVARIANT Detach() throw();
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bool Ownership(bool fOwns)
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{ return _Owns = fOwns; }
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protected:
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bool _Owns;
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};
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// Default constructor
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//
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inline auto_pv::auto_pv() throw()
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: _Owns(true)
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{
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::PropVariantInit(this);
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}
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// destructor
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inline auto_pv::~auto_pv() throw()
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{
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if(_Owns)
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::PropVariantClear(this);
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else
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::PropVariantInit(this);
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}
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// Clear the auto_var
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//
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inline void auto_pv::Clear() throw()
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{
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if(_Owns)
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::PropVariantClear(this);
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else
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::PropVariantInit(this);
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}
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inline void auto_pv::Attach(PROPVARIANT& varSrc) throw()
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{
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//
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// Free up previous VARIANT
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//
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Clear();
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//
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// Give control of data to auto_var
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//
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memcpy(this, &varSrc, sizeof(varSrc));
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varSrc.vt = VT_EMPTY;
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}
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inline PROPVARIANT auto_pv::Detach() throw()
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{
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PROPVARIANT varResult = *this;
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this->vt = VT_EMPTY;
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return varResult;
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}
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