C++ std::string and UTF-8

Question

Hello, I just want to write some few simple lines to a text file in C++, but I want them to be encoded in UTF-8. What is the easiest and simple way to do so?

Thanks

Answer 1

libiconv is a great library for all our encoding and decoding needs.

If you are using Windows you can use WideCharToMultiByte and specify that you want UTF8.

Answer 2

If by "simple" you mean ASCII, there is no need to do any encoding, since characters with an ASCII value of 127 or less are the same in UTF-8.

Answer 3

The only way UTF-8 affects 'std::string' is that size(), length(), and all the indices are measured in bytes, not characters.

And, as sbi points out, incrementing the iterator provided by std::string will step forward by byte, not by character, so it can actually point into the middle of a multibyte UTF-8 codepoint. There's no UTF-8-aware iterator provided in the standard library, but there are a few available on the 'Net.

If you remember that, you can put UTF-8 into std::string, write it to a file, etc. all in the usual way (by which I mean the way you'd use a std::string without UTF-8 inside.

You may want to start your file with a byte order mark so that other programs will know it is UTF-8.