C++ 在 std:wstring 中找到 std:string

Question

std::string targetDevice = "c53b1f8";
std::wstring devname;
VARIANT var;
var.vt = VT_BSTR;
pPropertyBag->Read(L"DevicePath", &var, 0);
devname = var.bstrVal;
VariantClear(&var);

if (devname.find(targetDevice) != std::string::npos) //<< my problem
{
...
}

What is the correct syntax for finding targetDevice in devname?

Answer 1

Problem is that different char size implies different character encoding. What is worse wchar_t size is platform dependent.

But assuming that you are interested in ASCII characters only and most encodings are compatible with ASCII you can use STL algorithm to do that checking:

template <typename A, typename B>
bool contains(const A& a, const B& b)
{
     return std::search(std::begin(a), std::end(a), 
                        std::begin(b), std::end(b)) != std::end(a);
}

https://godbolt.org/z/x4bajr

---

you should edit your question and provide more context why you need this functionality, since I suspect there is better way to resolve your actual problem.

Answer 2

Since this is Windows only as pPropertyBag->Read(L"DevicePath", &var, 0); is a Windows Direct Show call, I decided to just make targetDevice a wstring as well.