On Sat, 22 Jul 2023, 10:08 Lénárd Szolnoki via Std-Proposals, <
std-proposals_at_[hidden]> wrote:

> Hi,
>
> On Sat, 2023-07-22 at 11:42 +0300, sasho648 via Std-Proposals wrote:
> > I think a solution will be to outright ban such a conversion - where
> > an lvalue array to pointer conversion will not be allowed in context
> > where bool is expected.
>
> I agree that it's not ideal, but there are a lot of existing code that
> relies on the conversion of string literals to true. Mainly in the form
> of:
>
> assert(condition && "explanation");
>


Would this work if we made arrays contextually convertible to bool?

I can't think of any other valid uses for "is this array a null pointer? No
of course it isn't" (and this one is a bit of a "clever" hack anyway).


>
> https://codesearch.debian.net/search?q=assert%28.*%26%26+*%22.*%22%29&literal=0
>
> C compatibility should also be considered.
>
> clang seems to have -Wstring-conversion that finds this problematic
> conversion, it also seems to exclude the assert use case.
>
> Cheers,
> Lénárd
>
> >
> > On Sat, Jul 22, 2023 at 11:39 AM sasho648 <sasho648_at_[hidden]> wrote:
> > >
> > > int arr[2];
> > > bool test = arr;
> > > bool teststr = "string";
> > >
> > >
> > > Which I came across while having a function like this:
> > >
> > > void set_property(const char *name, const char *default_value);
> > > void set_property_bool(const char*name, bool default_value);
> > >
> > > Where I thought the bool one was expecting a string as second
> > > argument as well and so I wrote:
> > >
> > > set_property_bool("test", "true");
> > >
> > > Which compiled fine and even worked until I decided to change it
> > > to:
> > >
> > > set_property_bool("test", "false");
> > >
> > > In my opinion such a conversion holds no value - since it has only
> > > one outcome - and furthermore I think it's against C++ type safety
> > > - and even furthermore I think currently it's only purpose is
> > > obfuscation contests or creating hard to diagnose bugs as the case
> > > I've shown above.
>
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