What you're proposing looks like syntax sugar to save typing.

I think there are already numerous ways to do this, for example:

https://godbolt.org/z/1hjj9hEv5


On Sun, 13 Aug 2023 at 16:24, Frederick Virchanza Gotham via Std-Proposals <
std-proposals_at_[hidden]> wrote:

>
> What if we could set the type of what's thrown within a try block, as
> follows:
>
> try
> {
> throw = std::runtime_error;
>
> if ( something ) throw "bad happened";
>
> if ( something ) throw "worse happened;
>
> throw = std::logic_error;
>
> if ( something ) throw "even worse happened";
> }
>
> In the above snippet, the first two 'throw' statements throw an object of
> type 'runtime_error', and the third throws an object of type 'logic_error'.
>
> You could consider this feature to merely be a form of shorthand, but it
> could also be a versatile way of changing one line of code to affect much
> larger blocks of code.
>
> Of course the compiler would always need to know, at compile time, the
> type of what's thrown, and so you couldn't do the following:
>
> try
> {
> throw = std::runtime_error;
>
> if ( something ) throw "bad happened";
>
> if ( something ) throw "worse happened;
>
> if ( something ) throw = std::logic_error;
> else throw = std::domain_error;
>
> if ( something ) throw "even worse happened";
> }
>
> If you have nested try blocks inside a function, I think the "throw =
> type" should propagate into the nested blocks, however it should not
> propagate into a nested function call.
>
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>