How to initialize a const char* and/or const std::string in C++ with a sequence of UTF-8 character?

Question

How to initialize a const char* and/or const std::string in C++ with a sequence of UTF-8 characters?

I'm using a regular expression API that accepts UTF8 string as const char*. The initialization code should be platform independent.

Answer 1

This should work with any compiler:

const char* twochars = "\xe6\x97\xa5\xd1\x88";

Answer 2

Compiler - independent answer is also: Save the file in UTF-8 without BOM signature encoding.

const char* c = "ěščř"; //Just save the file in UTF-8 without BOM signature.

(See the comment of question.)
Btw, Windows console must bee set to UTF8. For many details see post into question.