how to convert string to wchar_t in c++

To convert a string to wchar_t in C++, you can use the std::wstring_convert class from the <locale> header. Here are the steps:

1. Include the necessary headers:

#include <locale>
#include <codecvt>

1. Create a std::wstring_convert object with a std::codecvt_utf8_utf16<wchar_t> facet:

std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>, wchar_t> converter;

This object will handle the conversion between UTF-8 and UTF-16.

1. Convert the string to wchar_t using the from_bytes member function of the std::wstring_convert object:

std::wstring wideStr = converter.from_bytes(str);

Here, str is the input string that you want to convert.

Let's put it all together in an example:

#include <locale>
#include <codecvt>
#include <string>

int main() {
  std::string str = "Hello, world!";

  std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>, wchar_t> converter;
  std::wstring wideStr = converter.from_bytes(str);

  return 0;
}

Now, wideStr will contain the converted wchar_t string.