Mastering the C++17 STL

A note on backslash-escaping

In this chapter, we'll be referring frequently to strings and regular expressions that contain literal backslashes. As you know, to write a string containing a literal backslash in C++, you have to escape the backslash with another backslash: thus "\n" represents a newline character but "\\n" represents the two-character string of "backslash" followed by "n". This kind of thing is usually easy to keep track of, but in this chapter we're going to have to take special pains. Regexes are implemented purely as a library feature; so when you write std::regex("\n") the regex library will see a "regex" containing only a single whitespace character, and if you write std::regex("\\n") the library will see a two-character ...