Reddit: why aren't people using D?

[Walter Bright]

Rainer Deyke wrote:
> Leandro Lucarella wrote:
>> !? It's true that in Python all are references, but there are inmutable
>> objects in Python, like int, float, strings and tuples. From a practical
>> POV it exactly the same as value types, if you do:
> 
> Immutable reference types are still reference types, and follow the same
> rules as other reference types.  You just can't modify them.  The
> assignment operator *always* rebinds a reference, regardless of the
> mutability or immutability of any objects involved.

 From a user's point of view, an immutable reference is 
indistinguishable from a value.


> But that's still not half as bad as D, where something simple like 'a =
> b; a.x = 5;' can have two completely different meanings depending on
> whether 'a' is a reference type or a value type.

True.

And in C++ with assignment overloads and copy constructors, one also has 
no clue what a.x=5 does without looking at the source to those functions.

I don't think there's anyway we can pretend to know what semantics a 
type has in a language with user-definable types without at least 
looking at its declaration.