Yeah that's fair - didn't think this through - well just don't use for then.

On Thu, Nov 9, 2023 at 2:24 PM Frederick Virchanza Gotham via Std-Proposals <std-proposals@lists.isocpp.org> wrote:

On Tue, Nov 7, 2023 at 12:14 PM sasho648 wrote:
>
> Anyone mentioned goto?  - With goto you can do exactly what the OP is asking for:
>
> for ( ; SerialSimGsm.available(); ++p )
> rev_con:
>             {
>                 if ( p >= &buf[sizeof(buf) - 1u] ) break;
>                 p[0u] = SerialSimGsm.read();
>                 p[1u] = '\0';
>                 unsigned const len = std::strlen(buf);
>                 char *ending = nullptr;
>                 if ( nullptr != (ending = std::strstr(buf, "\r\n")) )
>                 {
>                     ending[0u] = '\0';
>                     ending[1u] = '\0';  // Overwrite the "\r\n" with "\0\0"
>                     if ( ending != buf ) this->ProcessInput();
>                     buf[0u] = '\0';
>                     p = buf;
>                     goto rev_con;  // Don't allow 'p' to be incremented
>                 }
>             }



Your strategy causes an assertion failure in my code:

    https://godbolt.org/z/v6Px1Tao4

because your 'goto' is skipping the pre-iterative condition check.

Perhaps there should be four ways of continuing a loop:

    continue;                            // Don't skip anything
    continue(skip post);           // Skip the post-iterative step
    continue(skip pre);             // Skip the pre-iterative condition check
    continue(skip both);               // Skip both the post-iterative
step and the pre-iterative condition check

The four words 'skip, pre, post, both' would not be keywords in the
C++ language, but would be words with special meaning only when
encountered in parentheses following 'continue'.
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