@property - take it behind the woodshed and shoot it?

[Adam D. Ruppe]

On Thursday, 24 January 2013 at 22:04:02 UTC, Andrei Alexandrescu 
wrote:
> Properties are DATA, well except when you need to pass fields 
> by reference etc. at which point the syntactic glue comes 
> unglued.

An enum or a literal can't be passed by reference or otherwise 
have the address taken either, but we don't argue about if 
they're data or not, and don't change barely related parts of the 
language over them.

void foo(ref int a) {}

int b;
foo(b); // ok
foo(10); // nope

test.d(6): Error: function test.foo (ref int a) is not callable 
using argument types (int)
test.d(6): Error: constant 10 is not an lvalue


No big deal. Similarly:

enum c = 20;
foo(c);

test.d(12): Error: function test.foo (ref int a) is not callable 
using argument types (int)
test.d(12): Error: constant 20 is not an lvalue


Note: the error message betrays some truth about enum's 
implementation.... but who cares.


And finally:

@property int bar() { return 0; }
foo(bar);

test.d(9): Error: function test.foo (ref int a) is not callable 
using argument types (int)
test.d(9): Error: bar() is not an lvalue



Like the enum, we see a hint in the error message that the 
compiler is doing a little magic... but who cares.