On Thursday, 11 June 2020 08:53:56 PDT Tom Honermann via SG16 wrote:
> Agreed. It would be interesting to know if WG14 members have some
> historical perspective on this being implementation-defined. Perhaps
> Aaron can assist in getting an answer to that question. Copying the
> liason list...

Could be an ASCII-encoded source file being compiled to EBCDIC or vice-versa.
The preprocessor would run in the encoding of the source file, but the actual
compiler would translate into the execution character set, which won't match
the source character set.

Helps with writing source code without the need for digraphs or trigraphs.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
   Software Architect - Intel System Software Products