Re: function in an expression

>>  int& func( int& i ) { return ++i; }
>>  A = B[ func(i) ]  + B[ func(i) ];
>>
>> And they told me that write something similar is absolutely wrong.
>> Mine is just a nightmare or what they are telling me is true?
>
> Yes, that code is horrible. When reading it without seeing the
declaration
> of func() in view, I would guess that it should yield the same result
both
> times, so you can extract the call to func() and store it in a
tem****ary.

That's absolutely true, but nobody know what exactly func(i) do (what
about 
this function returns random values?). So my position is that the compiler

cannot decide to optimize in "any way" this expression because it will be
a 
huge error.

> However, it could also first invoke the left hand side of the addition
and
> then the right one:
>
>  int _1 = B[func(i)];
>  int _2 = B[func(i)];
>  A = _1 + _2;

I agree with you that this is a better way to write the same code.