Interfacing with C in 2.066.1

[Gary Willoughby via Digitalmars-d]

On Saturday, 8 November 2014 at 10:03:51 UTC, Jason den Dulk 
wrote:
> When upgrading my compiler from 2.065 to 2.066.1 I have 
> encountered problems with some of my extern(C) code.
>
> My declarations (in a .di file) are wrapped in an extern(C) 
> declaration. The code compiled fine in 2.065. In 2.066.1 it 
> first complained about functions returning "const char *" 
> ("function without this cannot be const"). After removing the 
> offending consts, it now complains of a missing "init" field of 
> a struct.
>
> It looks like its trying to access the stuff as D code rather 
> than C code. Can anyone shed some light on what the problem 
> might be?
>
> Thanks in advance
> Jason

This is highlighting the problem that using const in a function 
declaration can lead to confusion. Look at this example:

const char* foo()

Here const is interpreted as an attribute of the function not the 
char type. So defining it as a type constructor will remove the 
confusion like this:

const(char)* foo()

Here we are declaring a pointer to a const char which is (if 
you're interfacing with C) what you want. I'm assuming the 
compiler is being more strict about this now?

There was a forum thread somewhere detailing a proposition to 
only accept function attributes on the right of the declaration 
to avoid this confusion but i think it was just thoughts.

Have you got an example of the struct giving you problems?