Hi,

> Seems to me regex over istreams would be quite useful

Others have brought up points regarding separation of concerns, interface,
usefulness, and performance. I think this idea is a bit doomed from the
start: It seeks to combine an antiquated IO interface with an all but
deprecated(*) facet of the C++ standard library that has a lot of problems
itself.

I'd recommend looking at P1729 <http://wg21.link/P1729> which is hopefully
a modern approach we'll be moving towards.

Cheers,
Jeremy

*: std::regex has a lot of performance and API problems (e.g. no
string_view overloads), multiple widely used C++ best practices guidelines
recommend against the use of std::regex all together, and I've been told
the C++ committee isn't interested in trying to improve or fix std::regex
when they have higher priority items and high-quality third-party regex
libraries exist.


On Thu, Feb 20, 2025 at 7:48 AM Phil Bouchard via Std-Proposals <
std-proposals_at_[hidden]> wrote:

> Greetings,
>
> Seems to me regex over istreams would be quite useful. Here's an
> inefficient implementation:
>
>
> inline std::istream& operator >> (std::istream& in, std::string & v)
> {
> static const std::regex string_regex(R"(^\"(.*?)\"$)");
>
> std::smatch match;
>
> std::string x;
>
> for (x += in.get(); in; x += in.get())
> if (std::regex_match(x, match, string_regex))
> {
> v = match[1].str();
>
> return in;
> }
>
> throw std::invalid_argument("Parse error.");
> }
>
> Is there any interests in such implementation?
>
>
> Regards,
> --
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