CComVariant::GetSize
For simple-fixed size VARIANTs, this method returns the sizeof the underlying data type plus sizeof(VARTYPE).
ULONG GetSize() const;
Return Value
The size in bytes of the current contents of the CComVariant object.
Remarks
If the VARIANT contains an interface pointer, GetSize queries for IPersistStream or IPersistStreamInit. If successful, the return value is the low-order 32 bits of the value returned by GetSizeMax plus the sizeof a CLSID and sizeof(VARTYPE). If the interface pointer is NULL, GetSize returns the sizeof a CLSID plus sizeof(VARTYPE). If the total size is larger than ULONG_MAX, GetSize returns sizeof(VARTYPE) which indicates an error.
In all other cases, a temporary VARIANT of type VT_BSTR is coerced from the current VARIANT. The length of this BSTR is calculated as the size of the length of the string plus the length of the string itself plus the size of the null character plus sizeof(VARTYPE). If the VARIANT cannot be coerced to a VARIANT of type VT_BSTR, GetSize returns sizeof(VARTYPE).
The size returned by this method matches the number of bytes used by CComVariant::WriteToStream under successful conditions.
Requirements
Header: atlcomcli.h