Re: Question on building a variably modified type at parameter scope

[Eric Botcazou <ebotcazou at adacore dot com>]

> I believe this should be possible.  I believe that Ada has constructs
> like this.  I think you will need to use a PLACEHOLDER_EXPR to get the
> right thing to happen.

In Ada, we indeed have the mechanism in its full generality, i.e.

  struct S { int a; int b[a]; };

will work anywhere, and for this the PLACEHOLDER_EXPR machinery is needed.

But it seems to me that the case at stake is more specific:

  void f (struct S { int a; int b[s.a]; } s) { }

because struct S is defined at parameter scope and s.a is a known object, so 
perhaps the use of the (heavy) PLACEHOLDER_EXPR machinery could be avoided.

-- 
Eric Botcazou