[boomlinde]

IBM opposed their removal in C++1x

From http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n291...

> The biggest argument against deprecating trigraph is the fact that we know there are source code from world-wide companies, based on an internal survey of our customer problem reports that make heavy use of trigraphs for one reason or another, and customer testimonials. Google code search doesn't find them because these are proprietary code. Further discussions with some of these customers have shown serious dissatisfaction with WG21’s intention to deprecate trigraphs, because they do not wish to make any changes to their source code. It doesn't seem fair to force this group of existing users to change their source code for no apparent benefit, other then reducing an annoyance to another group.

ISO 646 is probably nowhere near as relevant to their argument as EBCDIC is.

> Trigraph deprecation is vexing for existing world-wide companies (of which IBM is one such user) because of their use of EBCDIC variant code pages. It makes it difficult to start in a code page neutral manner, establish what the active code page is, then start using invariant characters. We use a pragma filetag("IBM-1047") to toggle the code page, then we can use #. Prior to that we are in a code page neutral environment and must use the trigraph ??=