How to break const

[Mehrdad]

On Monday, 18 June 2012 at 15:13:33 UTC, deadalnix wrote:
>> Identical calls giving identical results? What?
>>
>>
>> import std.stdio;
>> struct S
>> {
>> this(int a)
>> {
>> this.a = a;
>> this.increment = { return this.a++; };
>> }
>> int a;
>> int delegate() pure increment;
>> auto oops() const { return this.increment(); }
>> }
>> void main()
>> {
>> auto c = immutable(S)(0);
>> writeln(c.oops()); // 0
>> writeln(c.oops()); // 1
>> writeln(c.oops()); // 2
>> writeln(c.oops()); // 3
>> writeln(c.oops()); // 4
>> writeln(c.oops()); // 5
>> }
>
> They are not call with the same parameters. The hidden 
> parameter have changed (I know this is tricky).


Explain it however you want.

The bottom line I'm getting at is, you can't re-order the calls, 
EVEN IF by "looking at them" you can tell they're pure @safe 
nothrow const...