convert std::string to const BYTE* for RegSetValueEx()

Question

I have a function that gets a std::string. That function calls

RegSetValueEx

the 5th parameter is the value of the registry value and expects a variable of t

Answer 1

The * 2 is because RegSetValueEx wants to know the number of bytes to write und each char (wchar_t) in a wstring is two bytes wide. So the resulting byte-array has twice the size!