Integer Vs Long Confusion

I've spent a lot of time working in the VBA environment and have every reason to believe that the claim in this article is at best, misleading.

I've never come across a situation where an automatic unexpected conversion is made. Of course, assignment by value to a larger type (such as a Double or Long) would be implicit.

One specific case where automatic conversion would be a breaking change would be an assignment to a Variant type. Without a conversion, the type would be VT_I2, with conversion VT_I4.

Passing an Integer type ByRef to a function expecting a Long emits a type mismatch in Office 2013.

I suspect they are referring to the internal storage of the Integer: it's very likely that they are not aligned on 16 bit words in memory (cf. a short structure member in C / C++). They are probably talking about that.

An integer declared as an Integer is still type checked as an Integer. The msdn documentation is referencing how the variable is stored internally. On a 32 bit system, an Integer will be stored in 32 BITS not Bytes, while on a 16 bit system the value is stored in a 16 BIT space or register, it would have been stored in 16. Hence the maximum size.

There is no type conversion going on as far as VBA is concerned. An int is an int and a long is a long, even though they now take up just as much space.