Frees the destination variant and makes a copy of the source VARIANTARG, performing the necessary indirection if the source is specified to be VT_BYREF.
The return value obtained from the returned HRESULT is one of the following.
The variant contains an array that is locked.
The source and destination have an invalid variant type (usually uninitialized).
Memory could not be allocated for the copy.
The argument pvargSrc was VT_ARRAY.
This function is useful when a copy of a variant is needed, and to guarantee that it is not VT_BYREF, such as when handling arguments in an implementation of IDispatch::Invoke.
For example, if the source is a (VT_BYREF | VT_I2), the destination will be a BYVAL | VT_I2. The same is true for all legal VT_BYREF combinations, including VT_VARIANT.
If pvargSrc is (VT_BYREF | VT_VARIANT), and the contained variant is VT_BYREF, the contained variant is also dereferenced.
This function frees any existing contents of pvarDest.