On Wednesday, 15 August 2018 at 15:31:14 UTC, 0xEAB wrote:
On Wednesday, 15 August 2018 at 14:58:40 UTC, Everlast wrote:
foo(x = 3);
C# 7 brought something similar for out params.
int.tryParse("1234", out int myNum);
Based on this approach, I would argue, that a reasonable syntax
would also contain the type, which leads to something like the
following:
foo(int x = 3);
foo(auto x = 3);
But I don't think this feature is worth having in D.
The whole point of the syntax is just sugar... although it does
reduce dependency issues ever so slightly. If one has to declare
the type it reduces it's effectiveness. Of course, if it is
necessary for some reason then it can be used. It obviously helps
reduce ambiguities but since D can infer the type from the
function then it shouldn't be necessary(but could be optional).
Basically auto could be implied when not explicit. This is a
little different than an isolated definition because D can infer
the type here in most cases(maybe templates would cause grief
though).
The point one really has to ask is what problems does it solve
and what problems does it create.
The problems it solves can be reduced typing and better
localization. It is minor, not a huge advancement, but the path
to heaven is paved with small stones.
The problems it creates: I can't think of any that do not already
steam from the base problem. If D has assignment syntax that can
be used inside function arguments then it would be ambiguous and
in that case the type would need to be required to solve that
problem.
