std::regex, to match begin/end of string

In JS regular expressions symbols ^ and $ designate start and end of the string. And only with /m modifier (multiline mode) they match start and end of line - position before and after CR/LF.

But in std::regex/ECMAscript mode symbols ^ and $ match start and end of line always.

Is there any way in std::regex to define start and end of the string match points? In other words: to support JavaScript multiline mode ...