Hey Dmytro,

I think the idea of allowing some conversions to be non-narrowing is fine
in principle; there are some parts that really need elaboration though.

I'm not really sure what the motivation here is for instance. The examples
with your wrapper class templates are contrived because in generic code,
you don't use list-initialization due other issues with narrowing
conversions and due to std::initializer_list constructors. You list
forwarding as a motivation, but perfect forwarding should never use
list-initialization in the first place.

I also don't find the argument that a library solution cannot work
convincing. List-initialization cannot cover loss of information between
possible future standard library types like std::big_int, between existing
types like std::complex, etc. There is no customization point to define
certain constructors as narrowing or "list-init-deleted", so preventing
information loss via list-initialization is incredibly half-baked. It may
have been a mistake in hindsight.

What I would like to see in the paper above all else is a concrete
real-world motivating example.

On Tue, 20 Jan 2026 at 12:08, Dmytro Ovdiienko via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> Hello,
>
> I'd like to submit the proposal regarding relaxing the narrowing int ->
> floating conversion.
>
> Abstract
>
> This paper proposes relaxing list-initialization narrowing rules so that
> an implicit conversion from an integer type to a floating-point type is not
> considered narrowing when the destination floating-point type adheres to
> ISO/IEC 60559, has a binary radix, and has sufficient precision to exactly
> represent all values of the source integer type.
>
> …
>
> The proposal is hosted on the GitHub. Following is a link:
>
> https://github.com/ujos/cplusplus-narrowing-cast/blob/draft_r0/PXXXXR0.md
>
> Could you give it a read and let me know if you have any comments.
>
>
> Kind regards
> Dmytro
>
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