On Wednesday, 8 October 2014 at 10:36:33 UTC, andre wrote:
Hi,
could you check whether it is correct, that second line in main
failes with a compiler error?
I think the compiler should be able to deduce the type without
explicitly passing it to the method call.
Kind regards
André
template ClassTemplate()
{
static auto deserialize(this MyType)()
{
return new MyType();
}
}
class A
{
mixin ClassTemplate;
}
void main()
{
A a = A.deserialize!A(); // Working
A b = A.deserialize(); // Not working
}
source\app.d(17): Error: template
app.A.ClassTemplate!().deserialize cannot dedu
ce function from argument types !()(), candidates are:
source\app.d(3): app.A.ClassTemplate!().deserialize(this
MyType)()
As far as I can tell, 'this' parameters don't work with static
methods. You can use typeof(this) instead:
----
template ClassTemplate()
{
static auto deserialize()
{
return new typeof(this)();
}
}
class A
{
mixin ClassTemplate;
}
void main()
{
A b = A.deserialize();
}
----
Be aware of the difference between template 'this' parameters and
typeof(this). A 'this' parameter is set to the (static) type of
the object, while typeof(this) is always the type of the
surrounding class.
----
class A
{
import std.stdio;
void printTypeofThis() {writeln(typeof(this).stringof);}
void printThisParameter(this T)() {writeln(T.stringof);}
}
class B : A {}
void main()
{
auto b = new B;
b.printTypeofThis(); /* "A", because the method is in A */
b.printThisParameter(); /* "B", because b is a B (statically)
*/
A a = b;
a.printThisParameter(); /* "A", because a is an A (statically)
*/
}
----
