Getting drive letter and information

#include <Windows.h>
#include <iostream>
#include <vector>
#include <tchar.h>
#include <string>
#include <sstream>

// Returns "(letter):\\"
std::string buildPath(const char, const std::string);

// returns the wstring version of string
std::wstring s_t_wstr(const std::string&);

int main()
{
	DWORD szDrives = ::GetLogicalDrives();
	std::vector<std::string> driveLetter;

	TCHAR fileSystemName[MAX_PATH + 1] = { 0 };
	TCHAR volumeName[MAX_PATH + 1] = { 0 };
	DWORD serialNumber = 0;
	DWORD maxComponentLen = 0;
	DWORD fileSystemFlags = 0;

	for (int i = 0; i < 26; i++) {
		if (szDrives & (1 << i)) {
			driveLetter.push_back(buildPath(_T('A') + i, ":\\"));
		}
	}

	for (auto path : driveLetter) {
		std::cout << "Path = " << path << std::endl;
		if (GetVolumeInformation(s_t_wstr(path).c_str(), volumeName, ARRAYSIZE(volumeName), &serialNumber, &maxComponentLen, &fileSystemFlags, fileSystemName, ARRAYSIZE(fileSystemName))) {
			std::wcout << "\tFile System Name: " << std::wstring(fileSystemName) << std::endl;
			std::wcout << "\tVolume Name: " << std::wstring(volumeName) << std::endl;
			std::wcout << "\tSerial Number: " << serialNumber << std::endl;
			std::wcout << "\tMax Component Length: " << maxComponentLen << std::endl << std::endl;
		}
		else
		{
			std::cout << "\tNo Volume Information\n" << std::endl;
		}
	}

	return 0;
}

std::string buildPath(const char c, const std::string str)
{
	std::stringstream sstream(c + str);
	std::string path;

	sstream >> path;

	return path;
}	// end buildPath

std::wstring s_t_wstr(const std::string& s)
{
	int len, slength = (int)s.length() + 1;

	len = MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, 0, 0);

	wchar_t* buf = new wchar_t[len];

	MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, buf, len);
	std::wstring r(buf);
	delete[] buf;
	return r;
}	// end s_t_wstr