How do I create a variant array of BSTR in Euphoria using EuCOM?

Question

So far I've figured out how to pass Unicode strings, bSTRs, to and from a Euphoria DLL using a Typelib. What I can't figure out, thus far, is how to create and pass back an array of BSTRs.

The code I have thus far (along with includes for EuCOM itself and parts of Win32lib):

global function REALARR()
  sequence seq
  atom psa
  atom var
  seq = { "cat","cow","wolverine" }
  psa = create_safearray( seq, VT_BSTR )
  make_variant( var, VT_ARRAY + VT_BSTR, psa )
  return var
end function

Part of the typelib is:

  [
     helpstring("get an array of strings"), 
     entry("REALARR")
  ] 
  void __stdcall REALARR( [out,retval] VARIANT* res );

And the test code, in VB6 is:

...
Dim v() as String
V = REALARR()
...

So far all I've managed to get is an error '0' from the DLL. Any ideas? Anyone?

Answer 1

You should use the create_safearray() function. It's documented (hidden?) under Utilities. Basically, put your BSTR pointers into a sequence and pass it to create_safearray():

sequence s, bstrs
s = {"A", "B"}
bstrs = {}
for i = 1 to length(s) do
    bstrs &= alloc_bstr( s[i] )
end for

atom array
array = create_safearray( bstrs, VT_BSTR )

...

destroy_safearray( array )