Re: Problems with CATLMap

"Igor Tandetnik" <>
Tue, 4 Mar 2008 12:02:32 -0500
geekgrrl <> wrote:

I'm trying to use CAtl map to store a map of string-based keys to a
VARIANT value, storing basically a key=value property bag.

My CAtlMap is declared as follows:
typedef CAtlMap< CComBSTR, VARIANT,CElementTraits<CComBSTR>>

Make it CAtlMap<CComBSTR, CComVariant, ...>

PropertyBagMap m_propbag_map ;

I'm adding the values as follows:

CComBSTR key = bstrPropertyName ;
CComVariant cvar( varValue ) ;
this->Lock() ;
this->m_propbag_map[ key ] = cvar ;
this->Unlock() ;

The left-hand side of the assignment is a raw VARIANT. Only a shallow
copy is performed - e.g., a BSTR pointer is copied, but not the
underlying string. Later cvar goes out of scope and frees the string in
its destructor. The VARIANT in the map is left with a dangling pointer.
With best wishes,
    Igor Tandetnik

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