• %u <e ee.com> Oct 08 2010
• bearophile <bearophileHUGS lycos.com> Oct 08 2010
• "Denis Koroskin" <2korden gmail.com> Oct 08 2010
• %u <e ee.com> Oct 08 2010

%u <e ee.com> writes:

/The following binary expressions are evaluated in an implementation-defined
order:
AssignExpression/../AddExpression/

/It is an error to depend on order of evaluation when it is not specified./

That makes this an error!?

y = x + 1;

Am I being paranoid or should I be adding more brackets?

bearophile <bearophileHUGS lycos.com> writes:

%u:

 That makes this an error!?
 
 y = x + 1;
 
 Am I being paranoid or should I be adding more brackets?


I presume this doesn't need other brackets.
And Walter has two or three times stated that he wants to eventually define the
order of evaluation in D (as C#/Java), I hope this will happen.

Bye,
bearophile

"Denis Koroskin" <2korden gmail.com> writes:

On Fri, 08 Oct 2010 18:49:36 +0400, %u <e ee.com> wrote:

 /The following binary expressions are evaluated in an  
 implementation-defined
 order:
 AssignExpression/../AddExpression/

 /It is an error to depend on order of evaluation when it is not  
 specified./

 That makes this an error!?

 y = x + 1;

 Am I being paranoid or should I be adding more brackets?


Assignment has higher precedence that addition so your code has no errors.

However, the following one does:

int x = 1;
int y = (x = 2) + x;

because "x" and "x = 2" has same precedence and thus may be evaluated in  
any order.

Stay away from such code and you should be fine.

%u <e ee.com> writes:

== Quote from Denis Koroskin (2korden gmail.com)'s article
 On Fri, 08 Oct 2010 18:49:36 +0400, %u <e ee.com> wrote:
 /The following binary expressions are evaluated in an
 implementation-defined
 order:
 AssignExpression/../AddExpression/

 /It is an error to depend on order of evaluation when it is not
 specified./

 That makes this an error!?

 y = x + 1;

 Am I being paranoid or should I be adding more brackets?





But you are right, I am confusing precedence and associativity.
The expressions page reads like there are only two levels of precedence, but it
only says anyting about the associativity.
A quick search on precedence shows that the C precedence rules apply.

 However, the following one does:
 int x = 1;
 int y = (x = 2) + x;
 because "x" and "x = 2" has same precedence and thus may be evaluated in
 any order.
 Stay away from such code and you should be fine.


I never assign within assignments :)