BSTR to std::string (std::wstring) and vice versa

Question

While working with COM in C++ the strings are usually of BSTR data type. Someone can use BSTR wrapper like CComBSTR or MS\'s CSt

Answer 1

BSTR to std::wstring:

// given BSTR bs
assert(bs != nullptr);
std::wstring ws(bs, SysStringLen(bs));

 
std::wstring to BSTR:

// given std::wstring ws
assert(!ws.empty());
BSTR bs = SysAllocStringLen(ws.data(), ws.size());

---

Doc refs:

1. std::basic_string::basic_string(const CharT*, size_type)
2. std::basic_string<>::empty() const
3. std::basic_string<>::data() const
4. std::basic_string<>::size() const
5. SysStringLen()
6. SysAllocStringLen()