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Subject: Re: [std-proposals] Labeled 'continue' and 'break'
From: Jorg Brown (jorg.brown_at_[hidden])
Date: 2020-03-10 22:26:19


I think you'd make a much more compelling case if this were a real
scenario, rather than merely a pseudo-random integer loop with
names like "x", "y", "z", "label1" and "label2". As it stands, the labels
don't provide any added value to this code.

With current C++, I'd have to write it this way:

int main() {
    for (int x = 0; x < 5; x++) {
        for (int y = 0; y < 5; y++) {
            for (int z = 0; z < 5; z++) {
                std::cout << x << ',' << y << ',' << z << std::endl;
                if (z + y == 8) goto continue_y_loop;
                if (z + x == 3) goto break_y_loop;
                if (x + y + z == 13) goto break_x_loop;
            }
            continue_y_loop:;
        }
        break_y_loop:;
    }
    break_x_loop:;
}

To be honest, that doesn't seem so bad.

= - = - = - =

May I ask: what scenario made you want to ask for this feature? Perhaps if
you show what you were really trying to do, it could be more compelling?

-- Jorg

On Tue, Mar 10, 2020 at 5:12 PM Ryan Nicholl via Std-Proposals <
std-proposals_at_[hidden]> wrote:

>
> I'd like to suggest adopting labeled break and continue statements,
>
> e.g.
>
> label1: for( int x = 0; x < 5; x++)
> {
> label2: for (int y = 0; y < 5; y++)
> {
> for (int z = 0; z < 5; z++)
> {
> std::cout << x << ',' << y << ',' << z << std::endl;
> if (z+y == 8) continue label2;
> if (z+x == 3) break label2;
> if (x + y + z == 13) break label1;
> }
> }
> }
>
> Other languages have it, and it's convenient with nested loops.
>
> --
> Std-Proposals mailing list
> Std-Proposals_at_[hidden]
> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
>



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