[fpc-pascal] Instances of interfaces ?

[Michael Van Canneyt]

On Fri, 10 Oct 2014, Adriaan van Os wrote:

> Section 7.1 Definition in Chapter 7 Interfaces of the FreePascal Language 
> Reference says
>
> 	"Instances of interfaces cannot be created directly: instead, an 
> instance of a class implementing the interface must be created."
>
> However, I assume that FreePascal classes (inheriting from interfaces) are 
> (unlike C++ classes) not binary compatible (on Win32) with interfaces ? In 
> other words, when I need to pass an instance of an interface to Win32 COM, I 
> have to call CoCreateInstance ?

No, you can pass the interface pointer directly:

MyIntf : IMyInterface;

begin
   MyIntf := MyClassInstance as IMyInterface;
end;

Then pass on MyIntf.

Michael.