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On Sun., Feb. 22, 2026, 9:07 a.m. Frederick Virchanza Gotham via
Std-Proposals, <std-proposals_at_[hidden]> wrote:

> On Fri, Feb 13, 2026 at 10:50 AM Peter Bindels wrote:
> >
> > You reinvented pattern matching.
> >
> > Try reading up on the pattern matching proposals.
> >
> > wg21.link/p2688
> > wg21.link/p1371
> > p0095, p1260, p1308, p2392, p2411, p3527, p3572, and many more.
> > Also maybe the Hagenberg EWG wiki for the discussions there, and why it
> is not in 26.
>
>
>
> I have finished implementing "switch class" in the GNU g++ compiler.
> Here's a GodBolt to try it out:
>
> https://godbolt.org/z/bnn94EGrE
>
> In the right-hand pane, you can edit the command line argument from
> 'frog' to something else to see what effect it has.
>
> The "switch class" statement is written as follows:
>
> switch class ( string_view(argv[1]) )
> {
> default:
> cout << "default\n";
> case "frog":
> cout << "frog\n";
> case "monkey":
> cout << "monkey\n";
> case "chocolate":
> case Func():
> ;
> }
>
> And essentially the compiler treats it as though you had written the
> following:
>
> switch ( 0 )
> {
> case 0:
> auto &&expr = string_view(argv[1]);
>
> if ( expr == "frog" ) goto __case_frog ;
> if ( expr == "monkey" ) goto __case_monkey ;
> if ( expr == "chocolate" ) goto __case_chocolate;
> if ( expr == Func() ) goto __case_Func ;
> goto __case_default;
>
> __case_default:
> cout << "default\n";
> __case_frog:
> cout << "frog\n";
> __case_monkey:
> cout << "monkey\n";
> __case_chocolate:
> __case_Func:
> ;
> }
>
> Note that this means that 'Func' will never get invoked if any of the
> first three cases match.
>
> Arthur pointed out to me about writing tests when adding new features
> to compilers . . . I've added about 7 or 8 features now to my patched
> GNU compiler, but I think I've broken some of the pre-exisiting tests.
> So before I can get started on writing tests, I need to go through
> those 7 or 8 features and fix the tests I broke. So I won't adding new
> compiler features for a while until I've corrected all the broken
> tests.
> --
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>