Affected subclause: [lex.phases]
Removal of trigraph support as a required feature.
Prevents accidental uses of trigraphs in non-raw string literals and comments.
Effect on original feature:
Valid C++ 2014 code that uses trigraphs may not be valid or may have different
semantics in this revision of C++.
Implementations may choose to
translate trigraphs as specified in C++ 2014 if they appear outside of a raw
string literal, as part of the
implementation-defined mapping from physical source file characters to
the basic source character set.