Array as a Class Member

Question

I\'m designing a dynamic buffer for outgoing messages. The data structure takes the form of a queue of nodes that have a Byte Array buffer as a member. Unfortunately in VB

Answer 1

So it turns out I needed a little help from OleAut32.dll, specifically the 'VariantCopy' function. This function faithfully makes an exact copy of one Variant to another, including when it is ByRef!

'clsTest

Private Declare Sub VariantCopy Lib "OleAut32" (pvarDest As Any, pvargSrc As Any)

Private m_Buffer() As Byte

Public Property Let Buffer(buf As Variant)
    m_Buffer = buf
End Property

Public Property Get Buffer() As Variant
    Buffer = GetByRefVariant(m_Buffer)
End Property

Private Function GetByRefVariant(ByRef var As Variant) As Variant
    VariantCopy GetByRefVariant, var
End Function

With this new definition, all the tests pass!

'mdlMain

Public Sub Main()
    Dim buf() As Byte
    ReDim buf(0 To 4)

    buf(0) = 1
    buf(1) = 2
    buf(2) = 3
    buf(3) = 4


    Dim oBuffer As clsTest
    Set oBuffer = New clsTest

    'Test #1, the assignment
    oBuffer.Buffer = buf    'Success!

    'Test #2, get the value of an index in the array
    Debug.Print oBuffer.Buffer()(2)    'Success!  This is from GSerg's comment on the question

    'Test #3, change the value of an index in the array and verify that it is actually modified
    oBuffer.Buffer()(2) = 27
    Debug.Print oBuffer.Buffer()(2)  'Success! Diplays "27" in the immediate window
End Sub