Add := digraph to D

[ixid]

I see that this is not going to happen for D2 but as a debate for 
a future D3 (and please just ignore my post if you find this in 
some way exasperating, I am interested but do not mean to cause 
friction):

Just as a question about the existing syntax as you listed 
combinations to learn as a negative:

> auto name = initializer;
> const name = initializer;
> immutable name = initializer;
> shared name = initializer;
> enum name = initializer;

After the first aren't these all just short hand for "const auto 
name = init" etc with the given keyword? If your argument is that 
additional cases are bad then this is a case for what appears to 
be syntactic reasons. It feels as if initialization should be 
more explicit than keyword varname. As a beginner I certainly 
found that odder than :=.

Syntax confusion with other languages is not a strong argument, 
well at least as the confusion is with unrelated languages. 
Fortran uses /= for not equal, Matlab uses ~=, while that is D's 
append to self.

Terse elegance is important in making languages quick to take in 
and work with, it's not an argument of new function but that is 
not the only reason to include features, convenience is a good 
reason when there is no ambiguity.