Re: warning: suggest parenthesis around assignment used as truth value

[John W. Eaton]

On 13-Mar-2009, Ben Abbott wrote:

| On Mar 13, 2009, at 9:40 AM, Rob Mahurin wrote:
| 
| > On Mar 12, 2009, at 9:08 PM, Ben Abbott wrote:
| >> Can someone explain what this warning is intended to imply?
| >>
| >>    warning: suggest parenthesis around assignment used as truth value
| >
| > This is a gcc warning? The idiom
| >     if (x=1) { ... }
| > is legal and useful but often a typo for
| >     if (x==1) { ... }
| > Extra parentheses
| >     if ((x=1)) { ... }
| > apparently suppress the warning.

The intent of the Octave warning is the same as the GCC warning.  In
what case is it emitted incorrectly?

| Your examples do give me some additional context for what is imlied.  
| Unfortunately, I've searched my sources and don't see such an instance  
| in my if/elseif statments. Further when I convert warnings to errors  
| ("warning error"), I get what looks like a parser error.

Using "warning error" will likely generate a lot of unwanted errors
from code that is distributed with Octave.  We should probably limit
these warnings to code that is not part of Octave itself.

jwe