I’m going to be upfront.
I may a bit biased when it comes to iostream.
I think it is irredeemably bad, there’s nothing good about it, I hate it to the core, and I rather see it replaced.
And extending it, feels to very much like a wasted effort.
I think is far more productive in the long run to have separate things that deal only with formatting (and extend that) and create an independent file or i/o interface that just does reads and writes without formatting.
From: Std-Proposals <std-proposals-bounces@lists.isocpp.org>
On Behalf Of Javier Estrada via Std-Proposals
Sent: Monday, February 10, 2025 7:01 PM
To: std-proposals@lists.isocpp.org
Cc: Javier Estrada <iphone.javier.estrada@gmail.com>
Subject: [std-proposals] std::bin manipulator for integer binary input/output
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.