Automatic translation of opUnary!"++" into opOpAssign!"+"

[Ali Çehreli via Digitalmars-d-learn]

On 12/28/2013 11:00 AM, monarch_dodra wrote:

 > On Saturday, 28 December 2013 at 15:37:06 UTC, Francesco Cattoglio wrote:
 >> So, while I was studying the apropriate template constraints for my
 >> shiny new iota implementation, I found out this funny thing:
 >>
 >> import std.stdio;
 >>
 >> class Test{
 >>     int x = 41;
 >>     Test opOpAssign(string op)(int rhs) if (op == "+") {
 >>          x += rhs;
 >>          return this;
 >>     }
 >> }
 >>
 >> void main() {
 >>     Test t1 = new Test;
 >>     //class Test has no opUnary defined, so the following
 >>     //gets automagically converted into (t1) += (1)
 >>     ++t1;
 >>     writeln(t1.x); //prints 42, correct!
 >> }
 >>
 >> This actually comes really handy, but I couldn't find it into the
 >> language documentation on dlang.org, so it surprised me.

Same here. I still can't find it in the documentation at least easily.

 >> Did I miss it in the language specification? Should we add it
 >> somewhere to the docs?
 >> Anyone with some spare time care to explain briefly what was the
 >> rationale behind this?
 >
 > I seem to remember that this is mentioned in TDPL? That's not spec of
 > course, but I think it's mentioned here.

I just checked again. No, I can't find it in TDPL.

 > I'm a bit fuzy about the shortcuts, but I *think* there are a couple
 > other shortcuts like this, such as "a += b" => "a = a + b"?

No, that translation is not there.

 > In any case, "http://dlang.org/operatoroverloading.html" needs to be
 > updated

Agreed.

Can someone who is familiar with the dmd source code enumerate such 
translations?

Thank you,
Ali