Bug 3511 – ref return property confused with property setter

import std.stdio; struct A { private int _prop = 42; ref int property() { return _prop; } //void property(in int rhs) { _prop = rhs; } } int main(string[] args) { A a; writeln( a.property ); a.property = 23; // produces the error below /* Error: function refProperty.A.property () is not callable using argument types (int) Error: expected 0 arguments, not 1 for non-variadic function type ref int() */ writeln( a.property ); return 0; } --- I think this is a bug, but it may actually be a "feature".

Yes, this is interesting "feature" but I think it should be marked to be so, be some kind of attributed: struct A { private int x_ = 42; @property @ref_getter_as_setter ref int x() { return x_; } } It still can be allowed without this properties, but then compile should emit warning. What do you think?

(In reply to comment #1) > Yes, this is interesting "feature" but I think it should be marked to be so, be > some kind of attributed: > > > struct A { > private int x_ = 42; > > @property > @ref_getter_as_setter > ref int x() { return x_; } > } > > It still can be allowed without this properties, but then compile should emit > warning. > > What do you think? I think that properties in general suck. The only thing I want is the syntax for omitting the parentheses when calling a function without arguments. I don't want the compiler transforming something like "a.property = 42;" into "a.property(42);". It seems so bizarre to me, but I must be in the minority. I would solve this problem by either introducing reference types like C++ or allowing alias this to alias to a dereferenced pointer: struct Ref(T) { T* _ref; alias *_ref this; this(ref T rhs) { _ref = &rhs; } } Then I could implement properties by doing something like this: struct A { private int _prop = 42; PropertyHelper property() { return PropertyHelper(_prop); } struct PropertyHelper { private int _p; private Ref!int _reference; alias _p this; // aliased to a copy this(ref int rhs) : _reference(rhs); // meh, I don't know how to do this in D { writeln("Log: called the getter"); _p = rhs; // note this is a copy } void opAssign(in int rhs) { writeln("Log: called the setter"); _reference = rhs; } } } But a problem could be that when doing "auto x = a.property;" the type of x would be PropertyHelper. I mean, personally I would just do int getProperty(); and void setProperty(int); and be done with it. Anyways, I think we need to provide more general functionality from the compiler so that cool things can be done with libraries (e.g. letting alias this do more like the example above).

*** Issue 5681 has been marked as a duplicate of this issue. ***

Issue 2736 is similar.

https://github.com/D-Programming-Language/dmd/commit/3d5f405babe65f65ebd2e1c92e9b84ee30eaee8d https://github.com/D-Programming-Language/dmd/commit/84e95255e51d02512935560de3424410ace1ba67