I was looking for a workaround to multiple alias this (or
opImplicitCast) the following trick doesn't work (why shouldn't
it ?). The error message is quite obscure to me.
import std.stdio;
class A(Derived)
{
alias cast(ref Derived)(this).x this;
}
class B : A!B
{
float x;
}
class C
Sent: Wednesday, June 11, 2014 at 8:07 PM
From: matovitch via Digitalmars-d-learn digitalmars-d-learn@puremagic.com
To: digitalmars-d-learn@puremagic.com
Subject: Multiple alias this failed workaround...obscure error message
I was looking for a workaround to multiple alias
On Wednesday, 11 June 2014 at 18:07:44 UTC, matovitch wrote:
source/app.d(5): Error: basic type expected, not cast
source/app.d(5): Error: no identifier for declarator int
source/app.d(5): Error: semicolon expected to close alias
declaration
source/app.d(5): Error: Declaration expected, not
On Wednesday, 11 June 2014 at 20:53:21 UTC, Jonathan M Davis via
Digitalmars-d-learn wrote:
I don't believe that it's legal to use a cast in an alias
declaration, and
that's certainly what the error seems to be indicating. Also,
using ref in a
cast is definitely illegal regardless of where
If I quote de documentation :
Any casting of a class reference to a derived class reference is
done with a runtime check to make sure it really is a downcast.
null is the result if it isn't. Note: This is equivalent to the
behavior of the dynamic_cast operator in C++.
I explicitly kept
On Wed, 11 Jun 2014 23:01:31 +
matovitch via Digitalmars-d-learn digitalmars-d-learn@puremagic.com
wrote:
About alias working with identifier but not with (runtime)
expression. Alias should work with compile time expression like
map!(x=2*x) right ? So a static cast should work isn't it ?
