Re: [boost] Boost.Charconv review runs January 15th - 25th, 2024

Hi, std::expected would be even better, just didn't think about it when I wrote the post. Basically just an easy to use version of std::stoi which takes a string_view as argument and does not throw. /Viktor On Wed, Jan 31, 2024 at 5:00 PM Peter Dimov via Boost wrote:

Dominique Devienne wrote:

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On Wed, Jan 31, 2024 at 1:38 PM Peter Dimov via Boost mailto:boost@lists.boost.org > wrote:

Viktor Sehr wrote: > I think boost::charconv should add one convenience function as follows: > // Returns std::nullopt on error > template <typename NumberType> > std::optional<NumberType> boost::charconv::to_number(const > std::string_view& sv) noexcept;

This throws away the error code

But sometimes that's all you want. That's kinda the point from Viktor I guess.

It's actually never what you want the way from_chars is specified, because 0.000[more 0...]001 fails with ERANGE, whereas 1.000[same 0...]001 succeeds and returns 1.0.

I don't really know of a use case where this is what one wants.

...

Not that an `expected` or `outcome` return type is bad; but it is more complex.

It's not any more complex for the user; the interface is the same as optional's if you don't need the error.

Returning `optional` is almost always a design mistake.

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