re2c makes it easy to drop into hand-written code where necessary. For example, in C backslash-newline makes a huge mess of everything unless you can handle it

re2c makes it easy to drop into hand-written code where necessary. For example, in C backslash-newline makes a huge mess of everything unless you can handle it underneath the lexer, which works nicely in re2c. In C++, raw string literals are not even context-free, let alone regular, so they have to be parsed with hand-written code. This is straightforward with re2c.