So like:

try(const Foo foo = build_foo()) {
  use_foo(foo); //here exceptions won't be handled by current try-catch
}
catch (...) { //handle only the declaration part
}

On Wed, Nov 22, 2023 at 3:00 PM sasho648 <sasho648_at_[hidden]> wrote:

> You mean have the try cover exception only in the parentheses and have the
> block scope only for using what's declared there?
>
> On Wed, Nov 22, 2023 at 2:55 PM Julien Jorge via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
>
>> On 22/11/2023 12:47, Giuseppe D'Angelo via Std-Proposals wrote:
>>
>> Il 22/11/23 12:31, sasho648 via Std-Proposals ha scritto:
>>
>>
>> So in my experience the biggest issue I had with using try-catch is for
>> example when I try to construct a reference within try-catch - in order to
>> capture only the exception that could occur there:
>>
>> try {
>> auto &ref = func();
>> }
>> catch(...) {
>> }
>>
>> Problem here is:
>>
>> You either have to use reference wrapper or something like that if you
>> want to handle only the exception that could potentially be thrown by func.
>> And still it would be ugly.
>>
>>
>> But what should `ref` refer to if `func()` throws?
>>
>> If I remember correctly, what Java does is that the scope of the variable
>> declared in the try statement is the try block, so it cannot be used
>> outside it. There is no such thing as `ref` if `func()` throws. I think
>> it's the way to go.
>>
>> By the way, such syntax would help for cases where we want to declare a
>> const value from something that can throw:
>>
>> try(const Foo foo = build_foo()) {
>> use_foo(foo);
>> }
>>
>> The current alternative is to either use a non-const variable that will
>> be set in the try block:
>>
>> Foo foo; // can't be const
>> try {
>> foo = build_foo();
>> } catch(...) {
>> return;
>> }
>> use_foo(foo);
>>
>> Or to put all the code in the try block:
>>
>> try {
>> const Foo foo = build_foo();
>> use_foo(foo);
>> } catch(...) {
>> // also catches exceptions thrown by use_foo().
>> return;
>> }
>>
>> None of these is satisfying IMHO.
>>
>> Julien
>> --
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>> Std-Proposals_at_[hidden]
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>>
>