std::uint64_t numbers above a certain value are not formatted correctly

[fedmos]

Boost version: 1.83.000
Compiler : GCC 13.2.0

std::uint64_t numbers above a certain value are not formatted correctly:
in the following minimal example first is formatted correctly (commas are used as separators), while second is not correctly formatted (no commas are used)

Example:

#include <iostream>
#include <iomanip>
#include <boost/format.hpp>
#include <boost/locale.hpp>

int main()
{
    boost::locale::generator gen;
    gen.categories(boost::locale::category_t::convert | boost::locale::category_t::formatting);
    auto locale = gen.generate("en_US.utf-8");
    
    std::stringstream output;
    output << boost::locale::as::number;
    output << std::setprecision(6);
    output.imbue(locale);
    
    std::uint64_t first = 9223372036854U;
    std::uint64_t second = 9223372036854775808U;
    
    output << first << " " << second;
    std::clog << output.str() << std::endl;
    return 0;
}

Console output:

9,223,372,036,854 9223372036854775808

[Flamefire]

The problem is that ICU only supports formatting int64_t numbers

• We use NumberFormat
• That accepts a Formattable
• And that is (among others) a double or int64_t but no uint64_t

So any integer value above INT32_MAX will be formatted using the classic locale. This is in line with how Boost.Locale handles things in general: Do the best it can and gracefully fall back to less functionality. In this case it is using the classic format.

I'm working on a solution