On Tue, Feb 11, 2025 at 7:28 AM Pavel Vazharov <freakpv_at_[hidden]> wrote:

>
>
> On Mon, Feb 10, 2025 at 9:34 PM Simon Schröder via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
> >
> > Well, I agree that we don‘t necessarily need any extensions of ostreams
> because we have std::format and std::print (though nothing equivalent to
> std::print for writing to files directly). But, there not a replacement for
> istreams, yet. Is there any proposal to replace istreams?
> The std::print(ln) functions can write to files
> <https://en.cppreference.com/w/cpp/io/print>. Or maybe I misunderstood
> you?
>

Ah, I actually didn't know that. But why is it a C file descriptor, which
is not RAII?

Still, we are missing something new for reading from files. Or did I miss
something else?

> >
> > Simon
> >
> > On Feb 10, 2025, at 7:31 PM, Jeremy Rifkin via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
> >
> > 
> > Hi,
> > I would be surprised if this hasn’t been proposed before. Now that we
> have std::format, I think it’s hard to make an argument for adding anything
> formatting-related to iostreams.
> >
> > Cheers,
> > Jeremy
> >
> > On Mon, Feb 10, 2025 at 12:01 Javier Estrada via Std-Proposals <
> std-proposals_at_[hidden]> wrote:
> >>
> >> There is a manipulator gap to read/write integer numbers in binary. As
> you well know, the standard manipulators are std::oct, std::dec, std::hex,
> which is essentially a format flag onto ios_base::basefield.
> >>
> >> Having a dedicated manipulator would close that gap and would eliminate
> the current "trick" of using std::bitset. The (abbreviated) example in
> cppreference .com reads:
> >>
> >> #include <bitset>
> >> #include <iostream>
> >>
> >> int main()
> >> {
> >> std::cout << "The number 42 in octal: " << std::oct << 42 << '\n'
> >> << "The number 42 in decimal: " << std::dec << 42 << '\n'
> >> << "The number 42 in hex: " << std::hex << 42 << '\n';
> >>
> >> // Note: there is no I/O manipulator that sets up a stream to print
> out
> >> // numbers in binary format (e.g. bin). If binary output is
> necessary
> >> // the std::bitset trick can be used:
> >> std::cout << "The number 42 in binary: " << std::bitset<8>{42} <<
> '\n';
> >>
> >> }
> >>
> >> With a std::bin manipulator:
> >>
> >> #include <iostream>
> >> #include <sstream>
> >>
> >> int main()
> >> {
> >>
> >> // This yields 101010
> >> std::cout << "The number 42 in binary: " << std::bin << 42 << '\n';
> >>
> >> }
> >>
> >>
> >> It would also take advantage of other manipulators, like std::setw and
> std::setfill:
> >>
> >>
> >> #include <iostream>
> >> #include <sstream>
> >>
> >> int main()
> >> {
> >>
> >> // This yields 00101010
> >>
> >> std::cout << std::setw(8) << std::setfill('0');
> >>
> >> std::cout << "The number 42 in binary: " << std::bin << 42 << '\n';
> >>
> >> }
> >>
> >>
> >> Reading binary numbers would also be addressed by the input streams.
> >>
> >>
> >> IF this proposal is considered, I see changes in:
> >>
> >> - A new bin flag in ios_base::basefield.
> >>
> >> - Support for the flag in ios_base::setf, ios_base::unsetf and
> ios_base::flags member functions.
> >>
> >> - Creation of the manipulator (similar to other manipulators) for the
> different char_traits
> >>
> >> - Support for binary parsing for input streams
> >>
> >> - Support for binary output for ostreams.
> >>
> >>
> >> std::ios_base in cppreference.com:
> >>
> >> https://en.cppreference.com/w/cpp/io/ios_base
> >>
> >>
> >> Integer I/O manipulators
> >>
> >> https://en.cppreference.com/w/cpp/io/manip/hex
> >>
> >>
> >> Regards,
> >>
> >> —Javier
> >>
> >>
> >>
> >> --
> >> Std-Proposals mailing list
> >> Std-Proposals_at_[hidden]
> >> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals
> >
> > --
> > Std-Proposals mailing list
> > Std-Proposals_at_[hidden]
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> >
> > --
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