CComSafeArray from _variant_t containing safe array
I get a _variant_t variant variable from a COM object method. This variant is actually of type SAFEARRAY of VARIANT. I'd like to use CComSafeArray to manipulate it.
Now I use the following code:
_variant_t v_sa = /*call to the object method*/
CComSafeArray<VARIANT> csa(v_sa.parray);
While this works, I've learnt from the CComSafeArray constructor documentation that
The constructor uses this address to make a copy of the array, so the array is not referenced after construction.
So, I'm probably making a redundant copy of the safe array. Is there a better way to construct CComSafeArray object?
The reason why a have to use _variant_t object is because it is returned by the code produced by the #import directive.
c++ com atl
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
add a comment |
I get a _variant_t variant variable from a COM object method. This variant is actually of type SAFEARRAY of VARIANT. I'd like to use CComSafeArray to manipulate it.
Now I use the following code:
_variant_t v_sa = /*call to the object method*/
CComSafeArray<VARIANT> csa(v_sa.parray);
While this works, I've learnt from the CComSafeArray constructor documentation that
The constructor uses this address to make a copy of the array, so the array is not referenced after construction.
So, I'm probably making a redundant copy of the safe array. Is there a better way to construct CComSafeArray object?
The reason why a have to use _variant_t object is because it is returned by the code produced by the #import directive.
c++ com atl
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
3
You need to use the "Attach" function. Also the _variant_t detach function.,
– Ben
Nov 25 '18 at 11:52
@Ben Ok,this seems to work: CComSafeArray<VARIANT> csa; csa.Attach(v_sa.Detach().parray); Is it correct?
– AlexVB
Nov 25 '18 at 12:01
1
You'll like Attach, but beware that the destructor will destroy the array. That is dangerous when you use variant_t, it will destroy it as well. You need to explicitly Detach(). Not using variant_t would be the easiest.
– Hans Passant
Nov 25 '18 at 12:25
add a comment |
I get a _variant_t variant variable from a COM object method. This variant is actually of type SAFEARRAY of VARIANT. I'd like to use CComSafeArray to manipulate it.
Now I use the following code:
_variant_t v_sa = /*call to the object method*/
CComSafeArray<VARIANT> csa(v_sa.parray);
While this works, I've learnt from the CComSafeArray constructor documentation that
The constructor uses this address to make a copy of the array, so the array is not referenced after construction.
So, I'm probably making a redundant copy of the safe array. Is there a better way to construct CComSafeArray object?
The reason why a have to use _variant_t object is because it is returned by the code produced by the #import directive.
c++ com atl
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
I get a _variant_t variant variable from a COM object method. This variant is actually of type SAFEARRAY of VARIANT. I'd like to use CComSafeArray to manipulate it.
Now I use the following code:
_variant_t v_sa = /*call to the object method*/
CComSafeArray<VARIANT> csa(v_sa.parray);
While this works, I've learnt from the CComSafeArray constructor documentation that
The constructor uses this address to make a copy of the array, so the array is not referenced after construction.
So, I'm probably making a redundant copy of the safe array. Is there a better way to construct CComSafeArray object?
The reason why a have to use _variant_t object is because it is returned by the code produced by the #import directive.
c++ com atl
c++ com atl
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
asked Nov 25 '18 at 11:46
AlexVBAlexVB
1237
1237
3
You need to use the "Attach" function. Also the _variant_t detach function.,
– Ben
Nov 25 '18 at 11:52
@Ben Ok,this seems to work: CComSafeArray<VARIANT> csa; csa.Attach(v_sa.Detach().parray); Is it correct?
– AlexVB
Nov 25 '18 at 12:01
1
You'll like Attach, but beware that the destructor will destroy the array. That is dangerous when you use variant_t, it will destroy it as well. You need to explicitly Detach(). Not using variant_t would be the easiest.
– Hans Passant
Nov 25 '18 at 12:25
add a comment |
3
You need to use the "Attach" function. Also the _variant_t detach function.,
– Ben
Nov 25 '18 at 11:52
@Ben Ok,this seems to work: CComSafeArray<VARIANT> csa; csa.Attach(v_sa.Detach().parray); Is it correct?
– AlexVB
Nov 25 '18 at 12:01
1
You'll like Attach, but beware that the destructor will destroy the array. That is dangerous when you use variant_t, it will destroy it as well. You need to explicitly Detach(). Not using variant_t would be the easiest.
– Hans Passant
Nov 25 '18 at 12:25
3
3
You need to use the "Attach" function. Also the _variant_t detach function.,
– Ben
Nov 25 '18 at 11:52
You need to use the "Attach" function. Also the _variant_t detach function.,
– Ben
Nov 25 '18 at 11:52
@Ben Ok,this seems to work: CComSafeArray<VARIANT> csa; csa.Attach(v_sa.Detach().parray); Is it correct?
– AlexVB
Nov 25 '18 at 12:01
@Ben Ok,this seems to work: CComSafeArray<VARIANT> csa; csa.Attach(v_sa.Detach().parray); Is it correct?
– AlexVB
Nov 25 '18 at 12:01
1
1
You'll like Attach, but beware that the destructor will destroy the array. That is dangerous when you use variant_t, it will destroy it as well. You need to explicitly Detach(). Not using variant_t would be the easiest.
– Hans Passant
Nov 25 '18 at 12:25
You'll like Attach, but beware that the destructor will destroy the array. That is dangerous when you use variant_t, it will destroy it as well. You need to explicitly Detach(). Not using variant_t would be the easiest.
– Hans Passant
Nov 25 '18 at 12:25
add a comment |
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3
You need to use the "Attach" function. Also the _variant_t detach function.,
– Ben
Nov 25 '18 at 11:52
@Ben Ok,this seems to work: CComSafeArray<VARIANT> csa; csa.Attach(v_sa.Detach().parray); Is it correct?
– AlexVB
Nov 25 '18 at 12:01
1
You'll like Attach, but beware that the destructor will destroy the array. That is dangerous when you use variant_t, it will destroy it as well. You need to explicitly Detach(). Not using variant_t would be the easiest.
– Hans Passant
Nov 25 '18 at 12:25