Long regex expression causes error

Question

This

std::regex line(\"[\\s]+\\+?[0-9]+.[0-9]+[\\s]+\\+?[0-9]+.[0-9]+[\\s]+\\+?[0-9]+.[0-9]+[\\s]\");

line causes this

Exceptio         


        

Answer 1

You either need to escape the back slashes with \\ (two for one), or use a raw string literal like this:

regex line{R"([\s]+\+?[0-9]+.[0-9]+[\s]+\+?[0-9]+.[0-9]+[\s]+\+?[0-9]+.[0-9]+[\s])"};

Raw string literals surround the string with (at least) R"( and )".

Read more about raw string literals HERE - Syntax (6).