std.format could support %{x,X} for ubyte[]

[dlangBugzillaToGithub]

pro.mathias.lang (@Geod24) reported this on 2021-04-18T18:22:47Z

Transfered from https://issues.dlang.org/show_bug.cgi?id=21843

CC List

• bugzilla (@WalterBright)

Description

```
import std;

void main ()
{
    ubyte[] data = [42, 69, 250];
    writefln("%X", data);
}
```

This currently throws an Exception. I think it could print `2A45FA`. This would be very handy to save on space when printing large ubyte arrays. This is an enhancement request, as there is nothing wrong with the current behavior.

[dlangBugzillaToGithub]

bugzilla (@WalterBright) commented on 2021-04-19T15:52:25Z

You can use

writefln!"%(%02X%)"(data);

to get the desired result. (But %X might be useful as a shortcut, so leaving this open.)