Testing the following in D
import std.stdio;
struct S
{
int _val;
@property ref int val() { return _val; }
@property void val(int v) { _val = v; writeln("Setter called!"); }
}
void main()
{
auto s = S();
s.val = 5;
}
yields "Settter called!"
as the output.
What rule does the compiler use to determine whether to call the first or the second implementation?
Here you are providing two @property
methods, one accepts an argument, the other does not. When doing s.val = 5;
, what you're actually doing is s.val(5)
, but as val
is a @property
you can write it as a property rather than a method call (see http://d-programming-language.org/function.html#property-functions). From s.val(5)
the compiler can do standard overload resolution - see http://d-programming-language.org/function.html#function-overloading.