On Thursday, 24 July 2014 at 11:39:13 UTC, Manu via Digitalmars-d wrote: 

Although... the more I think about it, the more I wonder why it matters if
the syntax is ambiguous when the name is taken in isolation, that never
actually happens...
Why can't it just mean 'either the template, or the default arg
instantiation', and be resolved when it's actually used?
Is it possible for templates or types to both appear in the same context
and create an actual ambiguity? What would that expression look like?
The only place I can imagine a conflict could occur would be within an is()
expression, but I'm not sure... can a uninstantiated template be used in an
is() expression where a type would also be a meaningful fit?

Generally, templates do this:
  T!()
And types do this:
  T var;

It's clear syntactically from 'T!()' that T is not a default args
instantiation of T, because it's involved in a template instantiation
expression.
It's also clear from 'T var' that T is not a template, because a variable
needs to have a type.

Seeing as templates can resolve to other templates, mixin templates, values, functions and types, the situation is complicated.