accessing dlls

I was thinking of moving some code in an app to a C++ dll to speed up the execution of some heavy loops. This will all be new to me so I have some concerns.

1) I would have to be able to pass UDTs as arguments .. is this possible? Anyone know where I can find a quick example?

2) How much will I have to give up in terms of debugging? Im guessing there is no way to run the VB prog in Debug and step into the C++ dll? How would you debug this sort of application?

3) Is it possible that the overhead of passing UDTs as arguments will negate the benefit of the increased speed of C++ ?

Thanks for any help!

Passing UDTs as arguments is simple. Just use

VB Code:

Public Declare Function xx Lib "xx.dll" ([b]UDT As MYTYPE[/b]) As Long

In VB, you can't step into a VC++ dll, so you either have to debug it in C++ or just assume that your DLL is error-free and assume all unidentifiable error as one in the DLL.

There is little overhead in passing UDTs since only a memory pointer is passed. Just make sure you don't change anything not meant to be changed!