Boost C++ Libraries: Ticket #7064: hex() with flag for lowercase output

Marshall Clow — Mon, 02 Jul 2012 15:17:08 GMT

Is there a use case here? Some existing piece of software that does unhex that only accepts lower case hex digits?

Mon, 02 Jul 2012 15:27:26 GMT

Yes. Existing software currently using lowercase output and not wanting to change the output just to take advantage of these Boost functions.

nigels.com@… — Fri, 29 Jan 2016 01:14:27 GMT

Agreed, I prefer to match the output of commandline sha256sum, than have to do the upper to lower case fix.

Marshall Clow — Fri, 29 Jan 2016 07:22:20 GMT

Olaf - I asked if there was "some piece of software that does unhex that only accepts lower case hex digits", and you said "Yes", but gave no examples.

Nigels - You prefer to match the output of sha256sum, but this isn't a checksuming routine. This encodes the bytes into a hex stream.

nigels.com@… — Fri, 29 Jan 2016 07:58:00 GMT

Hi Marhsall - my specific task was to convert binary hash to a hex string matching the output of sha256sum. It made me sad to have to write that manually, rather than use boost::algorithm::hex() A hex_lower() alternative, perhaps? I'd point out that hex_char_to_int already supports lower case.

Fri, 29 Jan 2016 08:11:21 GMT

Ah, I misread your question. I don't know if only lowercase is accepted, but I'd like to have full control over the output without having to pipe it through to_lower.

nigels.com@… — Sun, 31 Jan 2016 09:15:17 GMT

I proposed a patch on github: https://github.com/boostorg/algorithm/pull/14