2014R3 : AddressPtrMBS requires conversion from type Ptr to Memoryblock

SDKs Plugins
1

I have the following code, which works fine in 2014 R2.1 and MBS 14.3:

  dim p as ptr, offset as integer
  dim mb as memoryblock  
  [...]
  mb  = p.AddressPtrMBS(offset)

Under 2014R3, I’m getting the following error:

Extension method _Globals20.AddressPtrMBS requires a conversion from type Ptr to class MemoryBlock; use CType to explicitly convert first

But when I try it:

  mb  = CType(p,MemoryBlock).AddressPtrMBS(offset)  // this works
or
  mb  = MemoryBlock(p).AddressPtrMBS(offset)  // this doesn't work

I’m confused why CType works but casting doesn’t.

2

AddressMBS returns a ptr, so please use a ptr variable for the result.
Than you can assign to a memoryblock variable which triggers the automatically conversion.

this code works:

[code]dim m as new MemoryBlock(10)
dim p as ptr = m.AddressPtrMBS(0)
dim o as MemoryBlock = p

Break[/code]

The compiler used to automatically do conversion.

3

sorry, you did it other way. So you have p which is a ptr and call AddressPtrMBS on this. But AddressPtrMBS requires to be called on a memoryblock.
So first assign to memoryblock, than query new ptr:

[code] dim p as ptr, offset as integer
dim mb as memoryblock

dim temp as MemoryBlock = p
mb = temp.AddressPtrMBS(offset)[/code]

4

Thanks, Christian. I’m interested in why this change was made, as it seems to break code that is otherwise sensible, and the workaround looks somewhat clumsy.

On a side note, is this something you could fix within the plugin? e.g. have overloaded versions of AddressPtrMBS that handle memoryBlock and Ptr ?

5

I have no idea. We’ll see.

6

[quote=149890:@Michael Diehr]Under 2014R3, I’m getting the following error:

Extension method _Globals20.AddressPtrMBS requires a conversion from type Ptr to class MemoryBlock; use CType to explicitly convert first [/quote]

This is expected and documented:

CType performs a type conversion but casting basically reinterprets the value differently.

7

Thanks, Joe. I ran into another situation that’s similar, but different:

dim v as variant = "600x400"
dim w as integer
w = val(v.NthField("x",1))

Which also triggers the “requires a conversion… use CType” message

In this case, I fixed it using .StringValue:

dim v as variant = "600x400"
dim w as integer
w = val(v.StringValue.NthField("x",1))

I guess my overall question here : Is this fixing a bug or some edge case that wouldn’t compile or execute properly? Or is it more just a change in the compiler rules that had to happen for some other reason, but doesn’t really fix anything broken in these particular examples? Or…?

8

Also, is there any documentation on the difference between CType() and Casting, especially related to Variants and Ptr/MemoryBlocks?