Re: equality operator question

James Kanze <james.kanze@[EMAIL PROTECTED]
> writes:

> On May 5, 4:40 am, "barcaroller" <barcarol...@[EMAIL PROTECTED]
> wrote:
>> Is it now common practice to use conditional statements like
>
>>     if (0    == i)
>>     if (-1   == i)
>>     if (true == i)
>>     if (5    == i)
>
>> over the more traditional statements like
>
>>     if (i ==    0)
>>     if (i ==   -1)
>>     if (i == true)
>>     if (i ==    5)
>
>> for all types of 'i' (PODs and cl*****)?
>
> No.  First of all, you never compare with true or false.  As for
> the others, I'd say that it is generally universal practice to
> put the constant to the right of the comparision operator.  I
> don't know where this practice originated, but it certainly
> predates C++, and there's no reason to do otherwise in C++.

The reason is that if you have a normal keyboard, without rebound,
you'll type:

   if (i =   -1) ...

and then the compilers won't complain and will generate:

   { i=-1;
     ... }

On the other hand, if you write:

   if (-1 = i) ...

since -1 is not a LHS, -1=i is invalid and the compilers will signal
an error.


However, I cannot say that's it's common practice.
I prefer to write if(i==-1)...
and I just insert a grep in my makefiles to catch any assignment in
if, while or do conditionals.

-- 
__Pascal Bourguignon__