hex() with flag for lowercase output

[Olaf van der Spek <olafvdspek@…>]

Could you provide a paramter for hex() to indicate lowercase output is desired?

[Marshall Clow]

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

[Olaf van der Spek <olafvdspek@…>]

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

[nigels.com@…]

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

[Marshall Clow]

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@…]

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.

[Olaf van der Spek <olafvdspek@…>]

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@…]

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