char8_t formatting converts to integers

[cjdb]

#include <fmt/format.h>

int main()
{
    auto x = fmt::format(u8"{}", u8'a');

    for (auto const c : x) {
       fmt::print("{}", static_cast<char>(c));
    }
    fmt::print("\n");
}

The above program will format u8'a' as 97, not a. Is this to be expected, WIP, or a bug?

[vitaut]

Should print a. What compiler/flags? Seems to be working as expected on clang-1001.0.46.4 with -std=c++2a.

[vitaut]

Should be covered by this case:

fmt/include/fmt/core.h

Line 800 in af2c737

FMT_CONSTEXPR init<C, int, char_type> make_value(Char val) {

[cjdb]

What compiler/flags?

For the above example, on my Disco Docker:

root@acd1394df98b:/# g++-8 -std=c++2a -g -I fmt/include/ hello.cpp fmt/src/format.cc fmt/src/posix.cc -o hello
root@acd1394df98b:/# ./hello
a
root@acd1394df98b:/# g++-9 -std=c++2a -g -I fmt/include/ hello.cpp fmt/src/format.cc fmt/src/posix.cc -o hello
root@acd1394df98b:/# ./hello
97

Looks as though it's a GCC 9 regression.

[vitaut]

Could be some overload resolution weirdness, but I don't see how anything can be a better match than the Char overload above.

[vitaut]

Actually argument capture works fine. The problem is in lower level functions that have never been updated to handle exotic character types:

fmt/include/fmt/format.h

Line 2766 in 7e42c65

void write(wchar_t value) {

[vitaut]

Fixed in eddb84c.

[cjdb]

Thanks!