Is the difference observable?

Is the difference observable?

Of course, it is. the provision merely mentions the side-effect. the evaluations of certain expressions only include value computation, this is different. Also, I think using evaluation is better than a sole side effect in any case.

Is the difference observable?

Of course, it is. the provision merely mentions the side-effect. the evaluations of certain expressions only include value computation, this is different.

Obviously, I wasn't asking: will the replacement of «side-effect» with «evaluation» be observable by a reader of the paragraph.

The second sentence of [stmt.expr]/1 is an artifact from C++98/03 times, now there is [intro.execution]/9:

Every value computation and side effect associated with a full-expression is sequenced before every value computation and side effect associated with the next full-expression to be evaluated.

and the expression of an expression-statement is a full-expression. I'd say the sentence from [stmt.expr]/1 should be removed.

@languagelawyer I don't think it can be removed. the next statement is not necessary to be a full-expression, such as the if statement, it is not a full-expression as per [intro.execution] p5. If the next statement was a full-expression, I would say [intro.execution]/9 can cover what [stmt.expr]/1 says.

the next statement is not necessary to be a full-expression, such as the if statement, it is not a full-expression

Why is this a problem? The condition inside if parentheses is a full-expression, which is next to be evaluated.

the next statement is not necessary to be a full-expression, such as the if statement, it is not a full-expression

Why is this a problem? The condition inside if parentheses is a full-expression.

The execution of the condition is within the period of the execution of the if statement. That's the difference. [stmt.expr] p1 try to state the execution relationship between an expression-statement and the other statement.

What is the difference between saying that the evaluation completes before the next statement is executed and that it completes before the evaluation of the next full-expression (when the next statement execution starts with the evaluation of this full-expression)?

@languagelawyer Given an expression-statement A, a statement B that is not a full-expression, a full-expression C whose evaluation is within the execution of B.

Here are two utterances:

the evaluation of A is completed before the execution of B

the evaluation of A is completed before the evaluation of C

The first utterance can explicitly specify A -> B -> C. Instead, the second can only specify A-> C, we don't know whether A -> B or not. Symbol -> denotes completed before

Still don't get why one would need to know about A -> B or not, where symbol -> denotes completed before (whatever this means).

@languagelawyer I would say I haven't yet figured out a relevant example for this case(i.e. why we want to know A -> B)😅 . Maybe, "coroutine" would involve this domain? Since we have given that a full-expression is sequenced before the next full-expression, why don't we give a similar restriction for the execution relationship between expression-statement and the other statement(in most cases, it does not overlap with the previous provision except the next statement is also a full-expression)?

@languagelawyer Given an expression-statement A, a statement B that is not a full-expression, a full-expression C whose evaluation is within the execution of B.

Here are two utterances:

the evaluation of A is completed before the execution of B
the evaluation of A is completed before the evaluation of C

The first utterance can explicitly specify A -> B -> C. Instead, the second can only specify A-> C, we don't know whether A -> B or not. Symbol -> denotes completed before

I guess that the main problem is that "the execution of a statement" is not clearly specified. But I don't think we need to specify it, as doing so would not make difference.