Does dmd not always compile all of the source code?

[Gary Willoughby]

On Wednesday, 6 December 2017 at 16:47:17 UTC, A Guy With a 
Question wrote:
> abstract class Test(T)
> {
> private:
>     T thing;
>
> public:
>     this(T theThing)
>     {
>         thing = theThing;
> 	thisdoesnotexist(); // expect compiler error right here!!!!
>     }
> }
>
> ...but this compiles just fine.

It's because it's not being used in your program. How can the 
compiler compile it without knowing what T would be?

When you do this:

> class Test2
>    : Test!int
> {
>     this(int thing)
>     {
> 	super(thing);
>     }
> }

You are suppling T and now it is compiled and an error raised.