Why use MultiByteToWideCharArray to convert std::string to std::wstring?

Question

I want to convert a std::string to std::wstring. There are two approaches which i have come across.

1. Given a string str we cant convert into wide string using the following code wstring widestring = std::wstring(str.begin(),str.end());

2. The other approach is to use MultiByteToWideCharArray().

What i wanted to understand was what is the drawback of using the first approach and how does the second approach solves thing problem

Answer 1

MultiByteToWideChar offers more options(like the ability to select "codepages") and translates non-standard symbols correctly

Answer 2

The first option doesn't support multibyte encoding. It will iterate through each byte (char) in the string and convert it to a wide character. When you have a string with multibyte encoding, individual characters can take more than one byte, so a standard string iterator is inappropriate.

The MultiByteToWideChar function has support for different multibyte formats, as specified by the codepage parameter.