Precedence of GNU C++ extensions >? and <? (min/max operators)

Precedence of GNU C++ extensions >? and <? (min/max operators)

[Jeremy Hall]

Hi,

Does anyone know the exact priority of these operators?  Its not
mentioned in the
description of the extension as far as I can see.

Thanks
Jeremy

Re: Precedence of GNU C++ extensions >? and <? (min/max operators)

[Axel Freyn]

Hi Jeremy,

On Sat, Mar 05, 2011 at 10:07:01AM +0000, Jeremy Hall wrote:
> Does anyone know the exact priority of these operators?  Its not
> mentioned in the description of the extension as far as I can see.
As I read the documentation in the gcc-sourcecode, they are the same
precedence as "<", ">", "<=", ">=". They are relation operators and
form a "relational-expression": (§5.9 in C++ standard, [expr.rel])

See line 6258-6296 in
http://gcc.gnu.org/viewcvs/branches/gcc-4_5-branch/gcc/cp/parser.c?view=markup&revision=170622
relational-expression:
  shift-expression
  relational-expression < shift-expression
  relational-expression > shift-expression
  relational-expression <= shift-expression
  relational-expression >= shift-expression

GNU Extension:

relational-expression:
  relational-expression <? shift-expression
  relational-expression >? shift-expression 


HTH,

Axel

Re: Precedence of GNU C++ extensions >? and <? (min/max operators)

[Bob Plantz]

On 3/5/2011 2:07 AM, Jeremy Hall wrote:
> Hi,
>
> Does anyone know the exact priority of these operators?  Its not
> mentioned in the
> description of the extension as far as I can see.
>
> Thanks
> Jeremy
I always told my students that multiplication and division have
higher precedence than addition and subtraction. Use
parentheses everyplace else. Code readability was part of
their grade in my classes.

--Bob

Re: Precedence of GNU C++ extensions >? and <? (min/max operators)

[Jeremy Hall]

Thanks for looking this up Axel,
Exactly the info I needed.
(I am writing an arithmetic expression interpreter).

Regards
Jeremy