On Friday, 4 August 2017 at 09:38:59 UTC, Pippo wrote:
I'm trying to do something like this:
------------
module mylib.classA;
class A
{
@property string myproperty;
void function(ref A a) callToMyFunction;
void myfunction()
{
callToMyFunction(ref this);
}
}
------------
module myapp;
import mylib.classA;
int main()
{
A a = new A();
a.callToMyFunction = &myFunction;
a.myfunction();
}
void myFunction(ref A a)
{
writefln(a.myproperty);
}
------------
but (clearly) cannot compile. How can I get the same result?
Thank you in advance.
Your first error is actually this line:
callToMyFunction(ref this);
You can't use ref in a function call, only in function
declarations. But once that's fixed, you've got other errors in
the code you've posted -- you've declared main to return int, but
you return nothing; you're using writefln without importing it.
Also, class references are *already* references, so you don't
need to declare the function parameters as ref. Finally, although
this is not an error, @property has no effect on member
variables. It only applies to member functions. Also, you never
assign a value to myProperty, so even when the errors are fixed
nothing is printed.
Here's code that compiles and works as you expect:
class A
{
string myproperty;
void function(A a) callToMyFunction;
void myfunction()
{
callToMyFunction(this);
}
}
void main()
{
A a = new A();
a.callToMyFunction = &myFunction;
a.myproperty = "Hello";
a.myfunction();
}
void myFunction(A a)
{
import std.stdio : writefln;
writefln(a.myproperty);
}
Although you might change it to this:
class A
{
private string _myproperty;
private void function(A a) callToMyFunction;
this(string prop) { _myproperty = prop; }
@property string myproperty() { return _myproperty; }
void myfunction()
{
callToMyFunction(this);
}
}
void main()
{
A a = new A("Hello");
a.callToMyFunction = &myFunction;
a.myfunction();
}
void myFunction(A a)
{
import std.stdio : writefln;
writefln(a.myproperty);
}
