Win.h

/*
    SPDX-License-Identifier: MIT
    Copyright © 1991-2023 Amebis
    Copyright © 2016 GÉANT
*/
 
 
#pragma once
 
#include "Common.h"
#include <AclAPI.h>
#include <tlhelp32.h>
#include <winsvc.h>
#include <string>
#include <vector>
 
#pragma warning(push)
#pragma warning(disable: 4505) // Don't warn on unused code
 
 
template<class _Traits, class _Ax>
static DWORD GetModuleFileNameA(_In_opt_ HMODULE hModule, _Out_ std::basic_string<char, _Traits, _Ax> &sValue) noexcept
{
    assert(0); // TODO: Test this code.
 
    char szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(char)];
 
    // Try with stack buffer first.
    DWORD dwResult = ::GetModuleFileNameA(hModule, szStackBuffer, _countof(szStackBuffer));
    if (dwResult < _countof(szStackBuffer)) {
        // Copy from stack.
        sValue.assign(szStackBuffer, dwResult);
        return dwResult;
    } else {
        for (DWORD dwCapacity = 2*WINSTD_STACK_BUFFER_BYTES/sizeof(char);; dwCapacity *= 2) {
            // Allocate on heap and retry.
            std::unique_ptr<char[]> szBuffer(new char[dwCapacity]);
            dwResult = ::GetModuleFileNameA(hModule, szBuffer.get(), dwCapacity);
            if (dwResult < dwCapacity) {
                sValue.assign(szBuffer.get(), dwResult);
                return dwResult;
            }
        }
    }
}
 
template<class _Traits, class _Ax>
static DWORD GetModuleFileNameW(_In_opt_ HMODULE hModule, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sValue) noexcept
{
    wchar_t szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(wchar_t)];
 
    // Try with stack buffer first.
    DWORD dwResult = ::GetModuleFileNameW(hModule, szStackBuffer, _countof(szStackBuffer));
    if (dwResult < _countof(szStackBuffer)) {
        // Copy from stack.
        sValue.assign(szStackBuffer, dwResult);
        return dwResult;
    } else {
        for (DWORD dwCapacity = 2*WINSTD_STACK_BUFFER_BYTES/sizeof(wchar_t);; dwCapacity *= 2) {
            // Allocate on heap and retry.
            std::unique_ptr<wchar_t[]> szBuffer(new wchar_t[dwCapacity]);
            dwResult = ::GetModuleFileNameW(hModule, szBuffer.get(), dwCapacity);
            if (dwResult < dwCapacity) {
                sValue.assign(szBuffer.get(), dwResult);
                return dwResult;
            }
        }
    }
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) int GetWindowTextA(_In_ HWND hWnd, _Out_ std::basic_string<char, _Traits, _Ax> &sValue) noexcept
{
    assert(0); // TODO: Test this code.
 
    int iResult;
 
    // Query the final string length first.
    iResult = ::GetWindowTextLengthA(hWnd);
    if (iResult > 0) {
        if (++iResult < WINSTD_STACK_BUFFER_BYTES/sizeof(char)) {
            // Read string data to stack.
            char szBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(char)];
            iResult = ::GetWindowTextA(hWnd, szBuffer, _countof(szBuffer));
            sValue.assign(szBuffer, iResult);
        } else {
            // Allocate buffer on heap and read the string data into it.
            std::unique_ptr<char[]> szBuffer(new char[++iResult]);
            iResult = ::GetWindowTextA(hWnd, szBuffer.get(), iResult);
            sValue.assign(szBuffer.get(), iResult);
        }
        return iResult;
    }
 
    sValue.clear();
    return 0;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) int GetWindowTextW(_In_ HWND hWnd, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sValue) noexcept
{
    assert(0); // TODO: Test this code.
 
    int iResult;
 
    // Query the final string length first.
    iResult = ::GetWindowTextLengthW(hWnd);
    if (iResult > 0) {
        if (++iResult < WINSTD_STACK_BUFFER_BYTES/sizeof(wchar_t)) {
            // Read string data to stack.
            wchar_t szBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(wchar_t)];
            iResult = ::GetWindowTextW(hWnd, szBuffer, _countof(szBuffer));
            sValue.assign(szBuffer, iResult);
        } else {
            // Allocate buffer on heap and read the string data into it.
            std::unique_ptr<wchar_t[]> szBuffer(new wchar_t[++iResult]);
            iResult = ::GetWindowTextW(hWnd, szBuffer.get(), iResult);
            sValue.assign(szBuffer.get(), iResult);
        }
        return iResult;
    }
 
    sValue.clear();
    return 0;
}
 
template<class _Ty, class _Ax>
static _Success_(return != 0) BOOL GetFileVersionInfoA(_In_z_ LPCSTR lptstrFilename, __reserved DWORD dwHandle, _Out_ std::vector<_Ty, _Ax> &aValue) noexcept
{
    assert(0); // TODO: Test this code.
 
    // Get version info size.
    DWORD dwVerInfoSize = ::GetFileVersionInfoSizeA(lptstrFilename, &dwHandle);
    if (dwVerInfoSize != 0) {
        // Read version info.
        aValue.resize((dwVerInfoSize + sizeof(_Ty) - 1) / sizeof(_Ty));
        return ::GetFileVersionInfoA(lptstrFilename, dwHandle, dwVerInfoSize, aValue.data());
    } else
        return FALSE;
}
 
template<class _Ty, class _Ax>
static _Success_(return != 0) BOOL GetFileVersionInfoW(_In_z_ LPCWSTR lptstrFilename, __reserved DWORD dwHandle, _Out_ std::vector<_Ty, _Ax> &aValue) noexcept
{
    assert(0); // TODO: Test this code.
 
    // Get version info size.
    DWORD dwVerInfoSize = ::GetFileVersionInfoSizeW(lptstrFilename, &dwHandle);
    if (dwVerInfoSize != 0) {
        // Read version info.
        aValue.resize((dwVerInfoSize + sizeof(_Ty) - 1) / sizeof(_Ty));
        return ::GetFileVersionInfoW(lptstrFilename, dwHandle, dwVerInfoSize, aValue.data());
    } else
        return FALSE;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) DWORD ExpandEnvironmentStringsA(_In_z_ LPCSTR lpSrc, _Out_ std::basic_string<char, _Traits, _Ax> &sValue)
{
    assert(0); // TODO: Test this code.
 
    for (SIZE_T sSizeOut = SIZETAdd(strlen(lpSrc), 0x100);;) {
        if (sSizeOut > DWORD_MAX)
            throw std::invalid_argument("String too big");
        DWORD dwSizeIn = static_cast<DWORD>(sSizeOut);
        std::unique_ptr<char[]> szBuffer(new char[(size_t)dwSizeIn + 2]); // Note: ANSI version requires one extra char.
        sSizeOut = ::ExpandEnvironmentStringsA(lpSrc, szBuffer.get(), dwSizeIn);
        if (sSizeOut == 0) {
            // Error or zero-length input.
            break;
        } else if (sSizeOut <= dwSizeIn) {
            // The buffer was sufficient.
            sValue.assign(szBuffer.get(), sSizeOut - 1);
            return static_cast<DWORD>(sSizeOut);
        }
    }
 
    sValue.clear();
    return 0;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) DWORD ExpandEnvironmentStringsW(_In_z_ LPCWSTR lpSrc, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sValue)
{
    for (SIZE_T sSizeOut = SIZETAdd(wcslen(lpSrc), 0x100);;) {
        if (sSizeOut > DWORD_MAX)
            throw std::invalid_argument("String too big");
        DWORD dwSizeIn = static_cast<DWORD>(sSizeOut);
        std::unique_ptr<wchar_t[]> szBuffer(new wchar_t[(size_t)dwSizeIn + 1]);
        sSizeOut = ::ExpandEnvironmentStringsW(lpSrc, szBuffer.get(), dwSizeIn);
        if (sSizeOut == 0) {
            // Error or zero-length input.
            break;
        } else if (sSizeOut <= dwSizeIn) {
            // The buffer was sufficient.
            sValue.assign(szBuffer.get(), sSizeOut - 1);
            return static_cast<DWORD>(sSizeOut);
        }
    }
 
    sValue.clear();
    return 0;
}
 
template<class _Traits, class _Ax>
static VOID GuidToStringA(_In_ LPCGUID lpGuid, _Out_ std::basic_string<char, _Traits, _Ax> &str) noexcept
{
    assert(0); // TODO: Test this code.
 
    sprintf(str, "{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
        lpGuid->Data1,
        lpGuid->Data2,
        lpGuid->Data3,
        lpGuid->Data4[0], lpGuid->Data4[1],
        lpGuid->Data4[2], lpGuid->Data4[3], lpGuid->Data4[4], lpGuid->Data4[5], lpGuid->Data4[6], lpGuid->Data4[7]);
}
 
template<class _Traits, class _Ax>
static VOID GuidToStringW(_In_ LPCGUID lpGuid, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &str) noexcept
{
    assert(0); // TODO: Test this code.
 
    sprintf(str, L"{%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X}",
        lpGuid->Data1,
        lpGuid->Data2,
        lpGuid->Data3,
        lpGuid->Data4[0], lpGuid->Data4[1],
        lpGuid->Data4[2], lpGuid->Data4[3], lpGuid->Data4[4], lpGuid->Data4[5], lpGuid->Data4[6], lpGuid->Data4[7]);
}
 
#ifdef _UNICODE
#define GuidToString GuidToStringW
#else
#define GuidToString GuidToStringA
#endif
 
static _Success_(return) BOOL StringToGuidA(_In_z_ LPCSTR lpszGuid, _Out_ LPGUID lpGuid, _Out_opt_ LPCSTR *lpszGuidEnd = NULL) noexcept
{
    GUID g;
    LPSTR lpszEnd;
    unsigned long ulTmp;
    unsigned long long ullTmp;
 
    if (!lpszGuid || !lpGuid || *lpszGuid != '{') return FALSE;
    lpszGuid++;
 
    g.Data1 = strtoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE) return FALSE;
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ulTmp = strtoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ulTmp > 0xFFFF) return FALSE;
    g.Data2 = static_cast<unsigned short>(ulTmp);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ulTmp = strtoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ulTmp > 0xFFFF) return FALSE;
    g.Data3 = static_cast<unsigned short>(ulTmp);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ulTmp = strtoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ulTmp > 0xFFFF) return FALSE;
    g.Data4[0] = static_cast<unsigned char>((ulTmp >> 8) & 0xff);
    g.Data4[1] = static_cast<unsigned char>( ulTmp       & 0xff);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ullTmp = _strtoui64(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ullTmp > 0xFFFFFFFFFFFF) return FALSE;
    g.Data4[2] = static_cast<unsigned char>((ullTmp >> 40) & 0xff);
    g.Data4[3] = static_cast<unsigned char>((ullTmp >> 32) & 0xff);
    g.Data4[4] = static_cast<unsigned char>((ullTmp >> 24) & 0xff);
    g.Data4[5] = static_cast<unsigned char>((ullTmp >> 16) & 0xff);
    g.Data4[6] = static_cast<unsigned char>((ullTmp >>  8) & 0xff);
    g.Data4[7] = static_cast<unsigned char>( ullTmp        & 0xff);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '}') return FALSE;
    lpszGuid++;
 
    if (lpszGuidEnd)
        *lpszGuidEnd = lpszGuid;
 
    *lpGuid = g;
    return TRUE;
}
 
static _Success_(return) BOOL StringToGuidW(_In_z_ LPCWSTR lpszGuid, _Out_ LPGUID lpGuid, _Out_opt_ LPCWSTR *lpszGuidEnd = NULL) noexcept
{
    GUID g;
    LPWSTR lpszEnd;
    unsigned long ulTmp;
    unsigned long long ullTmp;
 
    if (!lpszGuid || !lpGuid || *lpszGuid != '{') return FALSE;
    lpszGuid++;
 
    g.Data1 = wcstoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE) return FALSE;
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ulTmp = wcstoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ulTmp > 0xFFFF) return FALSE;
    g.Data2 = static_cast<unsigned short>(ulTmp);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ulTmp = wcstoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ulTmp > 0xFFFF) return FALSE;
    g.Data3 = static_cast<unsigned short>(ulTmp);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ulTmp = wcstoul(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ulTmp > 0xFFFF) return FALSE;
    g.Data4[0] = static_cast<unsigned char>((ulTmp >> 8) & 0xff);
    g.Data4[1] = static_cast<unsigned char>( ulTmp       & 0xff);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '-') return FALSE;
    lpszGuid++;
 
    ullTmp = _wcstoui64(lpszGuid, &lpszEnd, 16);
    if (errno == ERANGE || ullTmp > 0xFFFFFFFFFFFF) return FALSE;
    g.Data4[2] = static_cast<unsigned char>((ullTmp >> 40) & 0xff);
    g.Data4[3] = static_cast<unsigned char>((ullTmp >> 32) & 0xff);
    g.Data4[4] = static_cast<unsigned char>((ullTmp >> 24) & 0xff);
    g.Data4[5] = static_cast<unsigned char>((ullTmp >> 16) & 0xff);
    g.Data4[6] = static_cast<unsigned char>((ullTmp >>  8) & 0xff);
    g.Data4[7] = static_cast<unsigned char>( ullTmp        & 0xff);
    lpszGuid = lpszEnd;
 
    if (*lpszGuid != '}') return FALSE;
    lpszGuid++;
 
    if (lpszGuidEnd)
        *lpszGuidEnd = lpszGuid;
 
    *lpGuid = g;
    return TRUE;
}
 
#ifdef _UNICODE
#define StringToGuid StringToGuidW
#else
#define StringToGuid StringToGuidA
#endif
 
template<class _Traits, class _Ax>
static LSTATUS RegQueryStringValue(_In_ HKEY hReg, _In_z_ LPCSTR pszName, _Out_ std::basic_string<char, _Traits, _Ax> &sValue) noexcept
{
    LSTATUS lResult;
    BYTE aStackBuffer[WINSTD_STACK_BUFFER_BYTES];
    DWORD dwSize = sizeof(aStackBuffer), dwType;
 
    // Try with stack buffer first.
    lResult = ::RegQueryValueExA(hReg, pszName, NULL, &dwType, aStackBuffer, &dwSize);
    if (lResult == ERROR_SUCCESS) {
        if (dwType == REG_SZ || dwType == REG_MULTI_SZ) {
            // The value is REG_SZ or REG_MULTI_SZ.
            dwSize /= sizeof(CHAR);
            sValue.assign(reinterpret_cast<LPCSTR>(aStackBuffer), dwSize && reinterpret_cast<LPCSTR>(aStackBuffer)[dwSize - 1] == 0 ? dwSize - 1 : dwSize);
        } else if (dwType == REG_EXPAND_SZ) {
            // The value is REG_EXPAND_SZ. Expand it from stack buffer.
            if (::ExpandEnvironmentStringsA(reinterpret_cast<LPCSTR>(aStackBuffer), sValue) == 0)
                lResult = ::GetLastError();
        } else {
            // The value is not a string type.
            lResult = ERROR_INVALID_DATA;
        }
    } else if (lResult == ERROR_MORE_DATA) {
        if (dwType == REG_SZ || dwType == REG_MULTI_SZ) {
            // The value is REG_SZ or REG_MULTI_SZ. Read it now.
            std::unique_ptr<CHAR[]> szBuffer(new CHAR[dwSize / sizeof(CHAR)]);
            if ((lResult = ::RegQueryValueExA(hReg, pszName, NULL, NULL, reinterpret_cast<LPBYTE>(szBuffer.get()), &dwSize)) == ERROR_SUCCESS) {
                dwSize /= sizeof(CHAR);
                sValue.assign(szBuffer.get(), dwSize && szBuffer[dwSize - 1] == 0 ? dwSize - 1 : dwSize);
            }
        } else if (dwType == REG_EXPAND_SZ) {
            // The value is REG_EXPAND_SZ. Read it and expand environment variables.
            std::unique_ptr<CHAR[]> szBuffer(new CHAR[dwSize / sizeof(CHAR)]);
            if ((lResult = ::RegQueryValueExA(hReg, pszName, NULL, NULL, reinterpret_cast<LPBYTE>(szBuffer.get()), &dwSize)) == ERROR_SUCCESS) {
                if (::ExpandEnvironmentStringsA(szBuffer.get(), sValue) == 0)
                    lResult = ::GetLastError();
            }
        } else {
            // The value is not a string type.
            lResult = ERROR_INVALID_DATA;
        }
    }
 
    return lResult;
}
 
template<class _Traits, class _Ax>
static LSTATUS RegQueryStringValue(_In_ HKEY hReg, _In_z_ LPCWSTR pszName, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sValue) noexcept
{
    LSTATUS lResult;
    BYTE aStackBuffer[WINSTD_STACK_BUFFER_BYTES];
    DWORD dwSize = sizeof(aStackBuffer), dwType;
 
    // Try with stack buffer first.
    lResult = ::RegQueryValueExW(hReg, pszName, NULL, &dwType, aStackBuffer, &dwSize);
    if (lResult == ERROR_SUCCESS) {
        if (dwType == REG_SZ || dwType == REG_MULTI_SZ) {
            // The value is REG_SZ or REG_MULTI_SZ.
            dwSize /= sizeof(WCHAR);
            sValue.assign(reinterpret_cast<LPCWSTR>(aStackBuffer), dwSize && reinterpret_cast<LPCWSTR>(aStackBuffer)[dwSize - 1] == 0 ? dwSize - 1 : dwSize);
        } else if (dwType == REG_EXPAND_SZ) {
            // The value is REG_EXPAND_SZ. Expand it from stack buffer.
            if (::ExpandEnvironmentStringsW(reinterpret_cast<LPCWSTR>(aStackBuffer), sValue) == 0)
                lResult = ::GetLastError();
        } else {
            // The value is not a string type.
            lResult = ERROR_INVALID_DATA;
        }
    } else if (lResult == ERROR_MORE_DATA) {
        if (dwType == REG_SZ || dwType == REG_MULTI_SZ) {
            // The value is REG_SZ or REG_MULTI_SZ. Read it now.
            std::unique_ptr<WCHAR[]> szBuffer(new WCHAR[dwSize / sizeof(WCHAR)]);
            if ((lResult = ::RegQueryValueExW(hReg, pszName, NULL, NULL, reinterpret_cast<LPBYTE>(szBuffer.get()), &dwSize)) == ERROR_SUCCESS) {
                dwSize /= sizeof(WCHAR);
                sValue.assign(szBuffer.get(), dwSize && szBuffer[dwSize - 1] == 0 ? dwSize - 1 : dwSize);
            }
        } else if (dwType == REG_EXPAND_SZ) {
            // The value is REG_EXPAND_SZ. Read it and expand environment variables.
            std::unique_ptr<WCHAR[]> szBuffer(new WCHAR[dwSize / sizeof(WCHAR)]);
            if ((lResult = ::RegQueryValueExW(hReg, pszName, NULL, NULL, reinterpret_cast<LPBYTE>(szBuffer.get()), &dwSize)) == ERROR_SUCCESS) {
                if (::ExpandEnvironmentStringsW(szBuffer.get(), sValue) == 0)
                    lResult = ::GetLastError();
            }
        } else {
            // The value is not a string type.
            lResult = ERROR_INVALID_DATA;
        }
    }
 
    return lResult;
}
 
template<class _Ty, class _Ax>
static LSTATUS RegQueryValueExA(_In_ HKEY hKey, _In_opt_z_ LPCSTR lpValueName, __reserved LPDWORD lpReserved, _Out_opt_ LPDWORD lpType, _Out_ std::vector<_Ty, _Ax> &aData) noexcept
{
    LSTATUS lResult;
    BYTE aStackBuffer[WINSTD_STACK_BUFFER_BYTES];
    DWORD dwSize = sizeof(aStackBuffer);
 
    // Try with stack buffer first.
    lResult = RegQueryValueExA(hKey, lpValueName, lpReserved, lpType, aStackBuffer, &dwSize);
    if (lResult == ERROR_SUCCESS) {
        // Copy from stack buffer.
        aData.resize((dwSize + sizeof(_Ty) - 1) / sizeof(_Ty));
        memcpy(aData.data(), aStackBuffer, dwSize);
    } else if (lResult == ERROR_MORE_DATA) {
        // Allocate buffer on heap and retry.
        aData.resize((dwSize + sizeof(_Ty) - 1) / sizeof(_Ty));
        lResult = RegQueryValueExA(hKey, lpValueName, lpReserved, NULL, reinterpret_cast<LPBYTE>(aData.data()), &dwSize);
    }
 
    return lResult;
}
 
template<class _Ty, class _Ax>
static LSTATUS RegQueryValueExW(_In_ HKEY hKey, _In_opt_z_ LPCWSTR lpValueName, __reserved LPDWORD lpReserved, _Out_opt_ LPDWORD lpType, _Out_ std::vector<_Ty, _Ax> &aData) noexcept
{
    LSTATUS lResult;
    BYTE aStackBuffer[WINSTD_STACK_BUFFER_BYTES];
    DWORD dwSize = sizeof(aStackBuffer);
 
    // Try with stack buffer first.
    lResult = RegQueryValueExW(hKey, lpValueName, lpReserved, lpType, aStackBuffer, &dwSize);
    if (lResult == ERROR_SUCCESS) {
        // Copy from stack buffer.
        aData.resize((dwSize + sizeof(_Ty) - 1) / sizeof(_Ty));
        memcpy(aData.data(), aStackBuffer, dwSize);
    } else if (lResult == ERROR_MORE_DATA) {
        // Allocate buffer on heap and retry.
        aData.resize((dwSize + sizeof(_Ty) - 1) / sizeof(_Ty));
        lResult = RegQueryValueExW(hKey, lpValueName, lpReserved, NULL, reinterpret_cast<LPBYTE>(aData.data()), &dwSize);
    }
 
    return lResult;
}
 
#if _WIN32_WINNT >= _WIN32_WINNT_VISTA
 
template<class _Traits, class _Ax>
static LSTATUS RegLoadMUIStringA(_In_ HKEY hKey, _In_opt_z_ LPCSTR pszValue, _Out_ std::basic_string<char, _Traits, _Ax> &sOut, _In_ DWORD Flags, _In_opt_z_ LPCSTR pszDirectory) noexcept
{
    // According to "Remarks" section in MSDN documentation of RegLoadMUIString(),
    // this function is defined but not implemented as ANSI variation.
    assert(0);
    return ERROR_CALL_NOT_IMPLEMENTED;
}
 
template<class _Traits, class _Ax>
static LSTATUS RegLoadMUIStringW(_In_ HKEY hKey, _In_opt_z_ LPCWSTR pszValue, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sOut, _In_ DWORD Flags, _In_opt_z_ LPCWSTR pszDirectory) noexcept
{
    LSTATUS lResult;
    wchar_t szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(wchar_t)];
    DWORD dwSize;
 
    Flags &= ~REG_MUI_STRING_TRUNCATE;
 
    // Try with stack buffer first.
    lResult = RegLoadMUIStringW(hKey, pszValue, szStackBuffer, sizeof(szStackBuffer), &dwSize, Flags, pszDirectory);
    if (lResult == ERROR_SUCCESS) {
        // Copy from stack buffer.
        sOut.assign(szStackBuffer, wcsnlen(szStackBuffer, dwSize/sizeof(wchar_t)));
    } else if (lResult == ERROR_MORE_DATA) {
        // Allocate buffer on heap and retry.
        std::unique_ptr<wchar_t[]> szBuffer(new wchar_t[(dwSize + sizeof(wchar_t) - 1)/sizeof(wchar_t)]);
        sOut.assign(szBuffer.get(), (lResult = RegLoadMUIStringW(hKey, pszValue, szBuffer.get(), dwSize, &dwSize, Flags, pszDirectory)) == ERROR_SUCCESS ? wcsnlen(szBuffer.get(), dwSize/sizeof(wchar_t)) : 0);
    }
 
    return lResult;
}
 
#endif
 
template<class _Traits, class _Ax>
static _Success_(return > 0) int NormalizeString(_In_ NORM_FORM NormForm, _In_ LPCWSTR lpSrcString, _In_ int cwSrcLength, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sDstString) noexcept
{
    WCHAR szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(WCHAR)];
 
    // Try to convert to stack buffer first.
    int cch = ::NormalizeString(NormForm, lpSrcString, cwSrcLength, szStackBuffer, _countof(szStackBuffer));
    if (cch > 0) {
        // Copy from stack.
        sDstString.assign(szStackBuffer, cwSrcLength != -1 ? wcsnlen(szStackBuffer, cch) : (size_t)cch - 1);
    } else {
        switch (::GetLastError()) {
            case ERROR_INSUFFICIENT_BUFFER:
                for (int i = 10; i--;) {
                    // Allocate buffer. Then convert again.
                    cch = -cch;
                    std::unique_ptr<WCHAR[]> szBuffer(new WCHAR[cch]);
                    cch = ::NormalizeString(NormForm, lpSrcString, cwSrcLength, szBuffer.get(), cch);
                    if (cch > 0) {
                        sDstString.assign(szBuffer.get(), cwSrcLength != -1 ? wcsnlen(szStackBuffer, cch) : (size_t)cch - 1);
                        break;
                    }
                    if (::GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
                        sDstString.clear();
                        break;
                    }
                }
                break;
 
            case ERROR_SUCCESS:
                sDstString.clear();
                break;
        }
    }
 
    return cch;
}
 
template<class _Traits1, class _Ax1, class _Traits2, class _Ax2>
static _Success_(return > 0) int NormalizeString(_In_ NORM_FORM NormForm, _In_ const std::basic_string<wchar_t, _Traits1, _Ax1> &sSrcString, _Out_ std::basic_string<wchar_t, _Traits2, _Ax2> &sDstString) noexcept
{
    WCHAR szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(WCHAR)];
 
    // Try to convert to stack buffer first.
    int cch = ::NormalizeString(NormForm, sSrcString.c_str(), (int)sSrcString.length(), szStackBuffer, _countof(szStackBuffer));
    if (cch > 0) {
        // Copy from stack.
        sDstString.assign(szStackBuffer, cch);
    } else {
        switch (::GetLastError()) {
            case ERROR_INSUFFICIENT_BUFFER:
                for (int i = 10; i--;) {
                    // Allocate buffer. Then convert again.
                    cch = -cch;
                    std::unique_ptr<WCHAR[]> szBuffer(new WCHAR[cch]);
                    cch = ::NormalizeString(NormForm, sSrcString.c_str(), (int)sSrcString.length(), szBuffer.get(), cch);
                    if (cch > 0) {
                        sDstString.assign(szBuffer.get(), cch);
                        break;
                    }
                    if (::GetLastError() != ERROR_INSUFFICIENT_BUFFER) {
                        sDstString.clear();
                        break;
                    }
                }
                break;
 
            case ERROR_SUCCESS:
                sDstString.clear();
                break;
        }
    }
 
    return cch;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) int WINAPI LoadStringA(_In_opt_ HINSTANCE hInstance, _In_ UINT uID, _Out_ std::basic_string<char, _Traits, _Ax> &sBuffer) noexcept
{
    // Get read-only pointer to string resource.
    LPCSTR pszStr;
    int i = LoadStringA(hInstance, uID, reinterpret_cast<LPSTR>(&pszStr), 0);
    if (i) {
        sBuffer.assign(pszStr, i);
        return i;
    } else
        return 0;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) int WINAPI LoadStringW(_In_opt_ HINSTANCE hInstance, _In_ UINT uID, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sBuffer) noexcept
{
    // Get read-only pointer to string resource.
    LPCWSTR pszStr;
    int i = LoadStringW(hInstance, uID, reinterpret_cast<LPWSTR>(&pszStr), 0);
    if (i) {
        sBuffer.assign(pszStr, i);
        return i;
    } else
        return 0;
}
 
static VOID OutputDebugStrV(_In_z_ LPCSTR lpOutputString, _In_ va_list arg) noexcept
{
    std::string str;
    try { vsprintf(str, lpOutputString, arg); } catch (...) { return; }
    OutputDebugStringA(str.c_str());
}
 
static VOID OutputDebugStrV(_In_z_ LPCWSTR lpOutputString, _In_ va_list arg) noexcept
{
    std::wstring str;
    try { vsprintf(str, lpOutputString, arg); } catch (...) { return; }
    OutputDebugStringW(str.c_str());
}
 
static VOID OutputDebugStr(_In_z_ LPCSTR lpOutputString, ...) noexcept
{
    va_list arg;
    va_start(arg, lpOutputString);
    OutputDebugStrV(lpOutputString, arg);
    va_end(arg);
}
 
static VOID OutputDebugStr(_In_z_ LPCWSTR lpOutputString, ...) noexcept
{
    va_list arg;
    va_start(arg, lpOutputString);
    OutputDebugStrV(lpOutputString, arg);
    va_end(arg);
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) int GetDateFormatA(_In_ LCID Locale, _In_ DWORD dwFlags, _In_opt_ const SYSTEMTIME *lpDate, _In_opt_z_ LPCSTR lpFormat, _Out_ std::basic_string<char, _Traits, _Ax> &sDate) noexcept
{
    int iResult = GetDateFormatA(Locale, dwFlags, lpDate, lpFormat, NULL, 0);
    if (iResult) {
        // Allocate buffer on heap and retry.
        std::unique_ptr<char[]> szBuffer(new char[iResult]);
        iResult = GetDateFormatA(Locale, dwFlags, lpDate, lpFormat, szBuffer.get(), iResult);
        sDate.assign(szBuffer.get(), iResult ? iResult - 1 : 0);
        return iResult;
    }
 
    return iResult;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) int GetDateFormatW(_In_ LCID Locale, _In_ DWORD dwFlags, _In_opt_ const SYSTEMTIME *lpDate, _In_opt_z_ LPCWSTR lpFormat, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sDate) noexcept
{
    int iResult = GetDateFormatW(Locale, dwFlags, lpDate, lpFormat, NULL, 0);
    if (iResult) {
        // Allocate buffer on heap and retry.
        std::unique_ptr<wchar_t[]> szBuffer(new wchar_t[iResult]);
        iResult = GetDateFormatW(Locale, dwFlags, lpDate, lpFormat, szBuffer.get(), iResult);
        sDate.assign(szBuffer.get(), iResult ? iResult - 1 : 0);
        return iResult;
    }
 
    return iResult;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) BOOL LookupAccountSidA(_In_opt_z_ LPCSTR lpSystemName, _In_ PSID lpSid, _Out_opt_ std::basic_string<char, _Traits, _Ax> *sName, _Out_opt_ std::basic_string<char, _Traits, _Ax> *sReferencedDomainName, _Out_ PSID_NAME_USE peUse) noexcept
{
    assert(0); // TODO: Test this code.
 
    DWORD dwNameLen = 0, dwRefDomainLen = 0;
 
    if (LookupAccountSidA(lpSystemName, lpSid,
        NULL, &dwNameLen     ,
        NULL, &dwRefDomainLen,
        peUse))
    {
        // Name and domain is blank.
        if (sName                ) sName                ->clear();
        if (sReferencedDomainName) sReferencedDomainName->clear();
        return TRUE;
    } else if (GetLastError() == ERROR_MORE_DATA) {
        // Allocate on heap and retry.
        std::unique_ptr<char[]> bufName     (new char[dwNameLen     ]);
        std::unique_ptr<char[]> bufRefDomain(new char[dwRefDomainLen]);
        if (LookupAccountSidA(lpSystemName, lpSid,
            bufName     .get(), &dwNameLen     ,
            bufRefDomain.get(), &dwRefDomainLen,
            peUse))
        {
            if (sName                ) sName                ->assign(bufName     .get(), dwNameLen      - 1);
            if (sReferencedDomainName) sReferencedDomainName->assign(bufRefDomain.get(), dwRefDomainLen - 1);
            return TRUE;
        }
    }
 
    return FALSE;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) BOOL LookupAccountSidW(_In_opt_z_ LPCWSTR lpSystemName, _In_ PSID lpSid, _Out_opt_ std::basic_string<wchar_t, _Traits, _Ax> *sName, _Out_opt_ std::basic_string<wchar_t, _Traits, _Ax> *sReferencedDomainName, _Out_ PSID_NAME_USE peUse) noexcept
{
    assert(0); // TODO: Test this code.
 
    DWORD dwNameLen = 0, dwRefDomainLen = 0;
 
    if (LookupAccountSidW(lpSystemName, lpSid,
        NULL, &dwNameLen     ,
        NULL, &dwRefDomainLen,
        peUse))
    {
        // Name and domain is blank.
        if (sName                ) sName                ->clear();
        if (sReferencedDomainName) sReferencedDomainName->clear();
        return TRUE;
    } else if (GetLastError() == ERROR_MORE_DATA) {
        // Allocate on heap and retry.
        std::unique_ptr<wchar_t[]> bufName     (new wchar_t[dwNameLen     ]);
        std::unique_ptr<wchar_t[]> bufRefDomain(new wchar_t[dwRefDomainLen]);
        if (LookupAccountSidW(lpSystemName, lpSid,
            bufName     .get(), &dwNameLen     ,
            bufRefDomain.get(), &dwRefDomainLen,
            peUse))
        {
            if (sName                ) sName                ->assign(bufName     .get(), dwNameLen      - 1);
            if (sReferencedDomainName) sReferencedDomainName->assign(bufRefDomain.get(), dwRefDomainLen - 1);
            return TRUE;
        }
    }
 
    return FALSE;
}
 
static _Success_(return != FALSE) BOOL CreateWellKnownSid(_In_ WELL_KNOWN_SID_TYPE WellKnownSidType, _In_opt_ PSID DomainSid, _Inout_ std::unique_ptr<SID> &Sid)
{
    BYTE szStackBuffer[WINSTD_STACK_BUFFER_BYTES];
    DWORD dwSize = sizeof(szStackBuffer);
 
    if (CreateWellKnownSid(WellKnownSidType, DomainSid, szStackBuffer, &dwSize)) {
        // The stack buffer was big enough to retrieve complete data. Alloc and copy.
        Sid.reset((SID*)new BYTE[dwSize]);
        memcpy(Sid.get(), szStackBuffer, dwSize);
        return TRUE;
    } else if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
        // The stack buffer was too small to retrieve complete data. Alloc and retry.
        Sid.reset((SID*)new BYTE[dwSize]);
        return CreateWellKnownSid(WellKnownSidType, DomainSid, Sid.get(), &dwSize);
    } else
        return FALSE;
}
 
template<class _Ty>
static _Success_(return != 0) BOOL GetTokenInformation(_In_ HANDLE TokenHandle, _In_ TOKEN_INFORMATION_CLASS TokenInformationClass, _Out_ std::unique_ptr<_Ty> &TokenInformation) noexcept
{
    BYTE szStackBuffer[WINSTD_STACK_BUFFER_BYTES];
    DWORD dwSize;
 
    if (GetTokenInformation(TokenHandle, TokenInformationClass, szStackBuffer, sizeof(szStackBuffer), &dwSize)) {
        // The stack buffer was big enough to retrieve complete data. Alloc and copy.
        TokenInformation.reset((_Ty*)(new BYTE[dwSize]));
        memcpy(TokenInformation.get(), szStackBuffer, dwSize);
        return TRUE;
    } else if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
        // The stack buffer was too small to retrieve complete data. Alloc and retry.
        TokenInformation.reset((_Ty*)(new BYTE[dwSize]));
        return GetTokenInformation(TokenHandle, TokenInformationClass, TokenInformation.get(), dwSize, &dwSize);
    } else
        return FALSE;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) BOOL QueryFullProcessImageNameA(_In_ HANDLE hProcess, _In_ DWORD dwFlags, _Inout_ std::basic_string<char, _Traits, _Ax>& sExeName)
{
    char szStackBuffer[WINSTD_STACK_BUFFER_BYTES / sizeof(char)];
    DWORD dwSize = _countof(szStackBuffer);
 
    // Try with stack buffer first.
    if (::QueryFullProcessImageNameA(hProcess, dwFlags, szStackBuffer, &dwSize)) {
        // Copy from stack.
        sExeName.assign(szStackBuffer, dwSize);
        return TRUE;
    }
    for (DWORD dwCapacity = 2 * WINSTD_STACK_BUFFER_BYTES / sizeof(char); GetLastError() == ERROR_INSUFFICIENT_BUFFER; dwCapacity *= 2) {
        // Allocate on heap and retry.
        std::unique_ptr<char[]> szBuffer(new char[dwCapacity]);
        dwSize = dwCapacity;
        if (::QueryFullProcessImageNameA(hProcess, dwFlags, szBuffer.get(), &dwSize)) {
            sExeName.assign(szBuffer.get(), dwSize);
            return TRUE;
        }
    }
    return FALSE;
}
 
template<class _Traits, class _Ax>
static _Success_(return != 0) BOOL QueryFullProcessImageNameW(_In_ HANDLE hProcess, _In_ DWORD dwFlags, _Inout_ std::basic_string<wchar_t, _Traits, _Ax>& sExeName)
{
    wchar_t szStackBuffer[WINSTD_STACK_BUFFER_BYTES / sizeof(wchar_t)];
    DWORD dwSize = _countof(szStackBuffer);
 
    // Try with stack buffer first.
    if (::QueryFullProcessImageNameW(hProcess, dwFlags, szStackBuffer, &dwSize)) {
        // Copy from stack.
        sExeName.assign(szStackBuffer, dwSize);
        return TRUE;
    }
    for (DWORD dwCapacity = 2 * WINSTD_STACK_BUFFER_BYTES / sizeof(wchar_t); GetLastError() == ERROR_INSUFFICIENT_BUFFER; dwCapacity *= 2) {
        // Allocate on heap and retry.
        std::unique_ptr<wchar_t[]> szBuffer(new wchar_t[dwCapacity]);
        dwSize = dwCapacity;
        if (::QueryFullProcessImageNameW(hProcess, dwFlags, szBuffer.get(), &dwSize)) {
            sExeName.assign(szBuffer.get(), dwSize);
            return TRUE;
        }
    }
    return FALSE;
}
 
 
#pragma warning(pop)
 
namespace winstd
{
 
    template<HANDLE INVALID>
    class win_handle : public handle<HANDLE, INVALID>
    {
        WINSTD_HANDLE_IMPL(win_handle, HANDLE, INVALID)
 
    public:
        virtual ~win_handle()
        {
            if (m_h != invalid)
                free_internal();
        }
 
    protected:
        void free_internal() noexcept override
        {
            CloseHandle(m_h);
        }
    };
 
    class library : public handle<HMODULE, NULL>
    {
        WINSTD_HANDLE_IMPL(library, HMODULE, NULL)
 
    public:
        virtual ~library()
        {
            if (m_h != invalid)
                free_internal();
        }
 
    protected:
        void free_internal() noexcept override
        {
            FreeLibrary(m_h);
        }
    };
 
    typedef win_handle<NULL> process;
 
    typedef win_handle<NULL> thread;
 
    typedef win_handle<INVALID_HANDLE_VALUE> process_snapshot;
 
    typedef win_handle<NULL> mutex;
 
    typedef win_handle<INVALID_HANDLE_VALUE> file;
 
    typedef win_handle<NULL> file_mapping;
 
    template <class _Ty> struct UnmapViewOfFile_delete
    {
        typedef UnmapViewOfFile_delete<_Ty> _Myt; 
 
        UnmapViewOfFile_delete() {}
 
        template <class _Ty2> UnmapViewOfFile_delete(const UnmapViewOfFile_delete<_Ty2>&) {}
 
        void operator()(_Ty* _Ptr) const
        {
            if (!UnmapViewOfFile(_Ptr))
                throw win_runtime_error("UnmapViewOfFile failed");
        }
    };
 
    template <class _Ty> struct UnmapViewOfFile_delete<_Ty[]>
    {
        typedef UnmapViewOfFile_delete<_Ty> _Myt; 
 
        UnmapViewOfFile_delete() {}
 
        void operator()(_Ty* _Ptr) const
        {
            if (!UnmapViewOfFile(_Ptr))
                throw win_runtime_error("UnmapViewOfFile failed");
        }
 
        template<class _Other>
        void operator()(_Other*) const
        {
            if (!UnmapViewOfFile(_Ptr))
                throw win_runtime_error("UnmapViewOfFile failed");
        }
    };
 
    typedef win_handle<NULL> event;
 
    class critical_section
    {
        WINSTD_NONCOPYABLE(critical_section)
        WINSTD_NONMOVABLE(critical_section)
 
    public:
        critical_section() noexcept
        {
            InitializeCriticalSection(&m_data);
        }
 
        virtual ~critical_section()
        {
            DeleteCriticalSection(&m_data);
        }
 
        operator LPCRITICAL_SECTION() noexcept
        {
            return &m_data;
        }
 
    protected:
        CRITICAL_SECTION m_data;    
    };
 
    class find_file : public handle<HANDLE, INVALID_HANDLE_VALUE>
    {
        WINSTD_HANDLE_IMPL(find_file, HANDLE, INVALID_HANDLE_VALUE)
 
    public:
        virtual ~find_file()
        {
            if (m_h != invalid)
                free_internal();
        }
 
    protected:
        void free_internal() noexcept override
        {
            FindClose(m_h);
        }
    };
 
    class heap : public handle<HANDLE, NULL>
    {
        WINSTD_HANDLE_IMPL(heap, HANDLE, NULL)
 
    public:
        virtual ~heap()
        {
            if (m_h != invalid)
                free_internal();
        }
 
        bool enumerate() noexcept
        {
            assert(m_h != invalid);
 
            bool found = false;
 
            // Lock the heap for exclusive access.
            HeapLock(m_h);
 
            PROCESS_HEAP_ENTRY e;
            e.lpData = NULL;
            while (HeapWalk(m_h, &e) != FALSE) {
                if ((e.wFlags & PROCESS_HEAP_ENTRY_BUSY) != 0) {
                    OutputDebugStr(
                        _T("Allocated block%s%s\n")
                        _T("  Data portion begins at: %#p\n  Size: %d bytes\n")
                        _T("  Overhead: %d bytes\n  Region index: %d\n"),
                            (e.wFlags & PROCESS_HEAP_ENTRY_MOVEABLE) != 0 ? tstring_printf(_T(", movable with HANDLE %#p"), e.Block.hMem).c_str() : _T(""),
                            (e.wFlags & PROCESS_HEAP_ENTRY_DDESHARE) != 0 ? _T(", DDESHARE") : _T(""),
                             e.lpData,
                             e.cbData,
                             e.cbOverhead,
                             e.iRegionIndex);
 
                    found = true;
                }
            }
 
            const DWORD dwResult = GetLastError();
            if (dwResult != ERROR_NO_MORE_ITEMS)
                OutputDebugStr(_T("HeapWalk failed (error %u).\n"), dwResult);
 
            // Unlock the heap.
            HeapUnlock(m_h);
 
            return found;
        }
 
    protected:
        void free_internal() noexcept override
        {
            enumerate();
            HeapDestroy(m_h);
        }
    };
 
    template <class _Ty>
    class heap_allocator
    {
    public:
        typedef typename _Ty value_type;    
 
        typedef _Ty *pointer;               
        typedef _Ty& reference;             
        typedef const _Ty *const_pointer;   
        typedef const _Ty& const_reference; 
 
        typedef SIZE_T size_type;           
        typedef ptrdiff_t difference_type;  
 
        template <class _Other>
        struct rebind
        {
            typedef heap_allocator<_Other> other;   
        };
 
    public:
        heap_allocator(_In_ HANDLE heap) : m_heap(heap)
        {
        }
 
        template <class _Other>
        heap_allocator(_In_ const heap_allocator<_Other> &other) : m_heap(other.m_heap)
        {
        }
 
        pointer allocate(_In_ size_type count)
        {
            assert(m_heap);
            return (pointer)HeapAlloc(m_heap, 0, count * sizeof(_Ty));
        }
 
        void deallocate(_In_ pointer ptr, _In_ size_type size)
        {
            UNREFERENCED_PARAMETER(size);
            assert(m_heap);
            HeapFree(m_heap, 0, ptr);
        }
 
        void construct(_Inout_ pointer ptr, _In_ const _Ty& val)
        {
            ::new ((void*)ptr) _Ty(val);
        }
 
        void construct(_Inout_ pointer ptr, _Inout_ _Ty&& val)
        {
            ::new ((void*)ptr) _Ty(std::forward<_Ty>(val));
        }
 
        void destroy(_Inout_ pointer ptr)
        {
            ptr->_Ty::~_Ty();
        }
 
        size_type max_size() const
        {
            return (SIZE_T)-1;
        }
 
    public:
        HANDLE m_heap;  
    };
 
    class actctx_activator
    {
        WINSTD_NONCOPYABLE(actctx_activator)
        WINSTD_NONMOVABLE(actctx_activator)
 
    public:
        actctx_activator(_In_ HANDLE hActCtx) noexcept
        {
            if (!ActivateActCtx(hActCtx, &m_cookie))
                m_cookie = 0;
        }
 
        virtual ~actctx_activator()
        {
            if (m_cookie)
                DeactivateActCtx(0, m_cookie);
        }
 
    protected:
        ULONG_PTR m_cookie; 
    };
 
    class impersonator
    {
    public:
        impersonator() noexcept : m_cookie(FALSE) {}
 
        virtual ~impersonator()
        {
            if (m_cookie)
                RevertToSelf();
        }
 
        operator bool () const { return m_cookie; }
 
    protected:
        BOOL m_cookie; 
    };
 
    class user_impersonator : public impersonator
    {
        WINSTD_NONCOPYABLE(user_impersonator)
        WINSTD_NONMOVABLE(user_impersonator)
 
    public:
        user_impersonator(_In_opt_ HANDLE hToken) noexcept
        {
            m_cookie = hToken && ImpersonateLoggedOnUser(hToken);
        }
    };
 
    class system_impersonator : public impersonator
    {
        WINSTD_NONCOPYABLE(system_impersonator)
        WINSTD_NONMOVABLE(system_impersonator)
 
    public:
        system_impersonator() noexcept
        {
            TOKEN_PRIVILEGES privileges = { 1, {{{ 0, 0 }, SE_PRIVILEGE_ENABLED }} };
            if (!LookupPrivilegeValue(NULL, SE_DEBUG_NAME, &privileges.Privileges[0].Luid) ||
                !ImpersonateSelf(SecurityImpersonation))
                return;
 
            {
                HANDLE h;
                if (!OpenThreadToken(GetCurrentThread(), TOKEN_ADJUST_PRIVILEGES, FALSE, &h))
                    goto revert;
                win_handle<INVALID_HANDLE_VALUE> thread_token(h);
                if (!AdjustTokenPrivileges(thread_token, FALSE, &privileges, sizeof(privileges), NULL, NULL))
                    goto revert;
                process_snapshot process_snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
                if (!process_snapshot)
                    goto revert;
                PROCESSENTRY32 entry = { sizeof(PROCESSENTRY32) };
                if (!Process32First(process_snapshot, &entry))
                    goto revert;
                while (_tcsicmp(entry.szExeFile, TEXT("winlogon.exe")) != 0)
                    if (!Process32Next(process_snapshot, &entry))
                        goto revert;
                process winlogon_process = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, entry.th32ProcessID);
                if (!winlogon_process)
                    goto revert;
                if (!OpenProcessToken(winlogon_process, TOKEN_IMPERSONATE | TOKEN_DUPLICATE, &h))
                    goto revert;
                win_handle<INVALID_HANDLE_VALUE> winlogon_token(h);
                if (!DuplicateToken(winlogon_token, SecurityImpersonation, &h))
                    goto revert;
                win_handle<INVALID_HANDLE_VALUE> duplicated_token(h);
                if (!SetThreadToken(NULL, duplicated_token))
                    goto revert;
            }
 
            m_cookie = TRUE;
            return;
 
        revert:
            DWORD dwResult = GetLastError();
            RevertToSelf();
            SetLastError(dwResult);
        }
    };
 
    class clipboard_opener
    {
    public:
        clipboard_opener(_In_opt_ HWND hWndNewOwner = NULL)
        {
            if (!OpenClipboard(hWndNewOwner))
                throw win_runtime_error("OpenClipboard failed");
        }
 
        virtual ~clipboard_opener()
        {
            CloseClipboard();
        }
    };
 
    class console_ctrl_handler
    {
        WINSTD_NONCOPYABLE(console_ctrl_handler)
        WINSTD_NONMOVABLE(console_ctrl_handler)
 
    public:
        console_ctrl_handler(_In_opt_ PHANDLER_ROUTINE HandlerRoutine) noexcept : m_handler(HandlerRoutine)
        {
            m_cookie = SetConsoleCtrlHandler(m_handler, TRUE);
        }
 
        virtual ~console_ctrl_handler()
        {
            if (m_cookie)
                SetConsoleCtrlHandler(m_handler, FALSE);
        }
 
    protected:
        BOOL m_cookie;              
        PHANDLER_ROUTINE m_handler; 
    };
 
    class vmemory : public handle<LPVOID, NULL>
    {
        WINSTD_NONCOPYABLE(vmemory)
 
    public:
        vmemory() noexcept : m_proc(NULL)
        {
        }
 
        vmemory(_In_ handle_type h, _In_ HANDLE proc) noexcept :
            m_proc(proc),
            handle<LPVOID, NULL>(h)
        {
        }
 
        vmemory(_Inout_ vmemory &&h) noexcept :
            m_proc(std::move(h.m_proc)),
            handle<LPVOID, NULL>(std::move(h))
        {
        }
 
        virtual ~vmemory()
        {
            if (m_h != invalid)
                VirtualFreeEx(m_proc, m_h, 0, MEM_RELEASE);
        }
 
        vmemory& operator=(_Inout_ vmemory &&other) noexcept
        {
            if (this != std::addressof(other)) {
                (handle<handle_type, NULL>&&)*this = std::move(other);
                m_proc                             = std::move(other.m_proc);
            }
            return *this;
        }
 
        void attach(_In_ HANDLE proc, _In_opt_ handle_type h) noexcept
        {
            m_proc = proc;
            if (m_h != invalid)
                free_internal();
            m_h    = h;
        }
 
        bool alloc(
            _In_     HANDLE hProcess,
            _In_opt_ LPVOID lpAddress,
            _In_     SIZE_T dwSize,
            _In_     DWORD  flAllocationType,
            _In_     DWORD  flProtect) noexcept
        {
            handle_type h = VirtualAllocEx(hProcess, lpAddress, dwSize, flAllocationType, flProtect);
            if (h != invalid) {
                attach(hProcess, h);
                return true;
            } else
                return false;
        }
 
    protected:
        void free_internal() noexcept override
        {
            VirtualFreeEx(m_proc, m_h, 0, MEM_RELEASE);
        }
 
    protected:
        HANDLE m_proc;  
    };
 
    class reg_key : public handle<HKEY, NULL>
    {
        WINSTD_HANDLE_IMPL(reg_key, HKEY, NULL)
 
    public:
        virtual ~reg_key()
        {
            if (m_h != invalid)
                free_internal();
        }
 
        bool delete_subkey(_In_z_ LPCTSTR szSubkey)
        {
            LSTATUS s;
 
            s = RegDeleteKey(m_h, szSubkey);
            if (s == ERROR_SUCCESS || s == ERROR_FILE_NOT_FOUND)
                return true;
 
            {
                reg_key k;
                handle_type h;
                s = RegOpenKeyEx(m_h, szSubkey, 0, KEY_ENUMERATE_SUB_KEYS, &h);
                if (s == ERROR_SUCCESS)
                    k.attach(h);
                else {
                    SetLastError(s);
                    return false;
                }
                for (;;) {
                    TCHAR szName[MAX_PATH];
                    DWORD dwSize = _countof(szName);
                    s = RegEnumKeyEx(k, 0, szName, &dwSize, NULL, NULL, NULL, NULL);
                    if (s == ERROR_SUCCESS)
                        k.delete_subkey(szName);
                    else if (s == ERROR_NO_MORE_ITEMS)
                        break;
                    else {
                        SetLastError(s);
                        return false;
                    }
                }
            }
 
            s = RegDeleteKey(m_h, szSubkey);
            if (s == ERROR_SUCCESS)
                return true;
            else {
                SetLastError(s);
                return false;
            }
        }
 
    protected:
        void free_internal() noexcept override
        {
            RegCloseKey(m_h);
        }
    };
 
    class security_id : public handle<PSID, NULL>
    {
        WINSTD_HANDLE_IMPL(security_id, PSID, NULL)
 
    public:
        virtual ~security_id()
        {
            if (m_h != invalid)
                free_internal();
        }
 
    protected:
        void free_internal() noexcept override
        {
            FreeSid(m_h);
        }
    };
 
    class process_information : public PROCESS_INFORMATION
    {
        WINSTD_NONCOPYABLE(process_information)
        WINSTD_NONMOVABLE(process_information)
 
    public:
        process_information() noexcept
        {
            hProcess    = INVALID_HANDLE_VALUE;
            hThread     = INVALID_HANDLE_VALUE;
            dwProcessId = 0;
            dwThreadId  = 0;
        }
 
        ~process_information()
        {
            #pragma warning(push)
            #pragma warning(disable: 6001) // Using uninitialized memory '*this'. << ???
 
            if (hProcess != INVALID_HANDLE_VALUE)
                CloseHandle(hProcess);
 
            if (hThread != INVALID_HANDLE_VALUE)
                CloseHandle(hThread);
 
            #pragma warning(pop)
        }
    };
 
    class event_log : public handle<HANDLE, NULL>
    {
        WINSTD_HANDLE_IMPL(event_log, HANDLE, NULL)
 
    public:
        virtual ~event_log()
        {
            if (m_h != invalid)
                free_internal();
        }
 
    protected:
        void free_internal() noexcept override
        {
            DeregisterEventSource(m_h);
        }
    };
 
    class sc_handle : public handle<SC_HANDLE, NULL>
    {
        WINSTD_HANDLE_IMPL(sc_handle, SC_HANDLE, NULL)
 
    public:
        virtual ~sc_handle()
        {
            if (m_h != invalid)
                free_internal();
        }
 
    protected:
        void free_internal() noexcept override
        {
            CloseServiceHandle(m_h);
        }
    };
 
}
 
 
#pragma warning(push)
#pragma warning(disable: 4505) // Don't warn on unused code
 
static LSTATUS RegCreateKeyExA(
    _In_ HKEY hKey,
    _In_ LPCSTR lpSubKey,
    _Reserved_ DWORD Reserved,
    _In_opt_ LPSTR lpClass,
    _In_ DWORD dwOptions,
    _In_ REGSAM samDesired,
    _In_opt_ CONST LPSECURITY_ATTRIBUTES lpSecurityAttributes,
    _Inout_ winstd::reg_key &result,
    _Out_opt_ LPDWORD lpdwDisposition)
{
    HKEY h;
    LSTATUS s = RegCreateKeyExA(hKey, lpSubKey, Reserved, lpClass, dwOptions, samDesired, lpSecurityAttributes, &h, lpdwDisposition);
    if (s == ERROR_SUCCESS)
        result.attach(h);
    return s;
}
 
static LSTATUS RegCreateKeyExW(
    _In_ HKEY hKey,
    _In_ LPCWSTR lpSubKey,
    _Reserved_ DWORD Reserved,
    _In_opt_ LPWSTR lpClass,
    _In_ DWORD dwOptions,
    _In_ REGSAM samDesired,
    _In_opt_ CONST LPSECURITY_ATTRIBUTES lpSecurityAttributes,
    _Inout_ winstd::reg_key &result,
    _Out_opt_ LPDWORD lpdwDisposition)
{
    HKEY h;
    LSTATUS s = RegCreateKeyExW(hKey, lpSubKey, Reserved, lpClass, dwOptions, samDesired, lpSecurityAttributes, &h, lpdwDisposition);
    if (s == ERROR_SUCCESS)
        result.attach(h);
    return s;
}
 
static LSTATUS RegOpenKeyExA(
    _In_ HKEY hKey,
    _In_opt_ LPCSTR lpSubKey,
    _In_opt_ DWORD ulOptions,
    _In_ REGSAM samDesired,
    _Inout_ winstd::reg_key &result)
{
    HKEY h;
    LSTATUS s = RegOpenKeyExA(hKey, lpSubKey, ulOptions, samDesired, &h);
    if (s == ERROR_SUCCESS)
        result.attach(h);
    return s;
}
 
static LSTATUS RegOpenKeyExW(
    _In_ HKEY hKey,
    _In_opt_ LPCWSTR lpSubKey,
    _In_opt_ DWORD ulOptions,
    _In_ REGSAM samDesired,
    _Inout_ winstd::reg_key &result)
{
    HKEY h;
    LSTATUS s = RegOpenKeyExW(hKey, lpSubKey, ulOptions, samDesired, &h);
    if (s == ERROR_SUCCESS)
        result.attach(h);
    return s;
}
 
static BOOL OpenProcessToken(_In_ HANDLE ProcessHandle, _In_ DWORD DesiredAccess, _Inout_ winstd::win_handle<NULL> &TokenHandle)
{
    HANDLE h;
    if (OpenProcessToken(ProcessHandle, DesiredAccess, &h)) {
        TokenHandle.attach(h);
        return TRUE;
    }
    return FALSE;
}
 
static BOOL DuplicateTokenEx(_In_ HANDLE hExistingToken, _In_ DWORD dwDesiredAccess, _In_opt_ LPSECURITY_ATTRIBUTES lpTokenAttributes, _In_ SECURITY_IMPERSONATION_LEVEL ImpersonationLevel, _In_ TOKEN_TYPE TokenType, _Inout_ winstd::win_handle<NULL> &NewToken)
{
    HANDLE h;
    if (DuplicateTokenEx(hExistingToken, dwDesiredAccess, lpTokenAttributes, ImpersonationLevel, TokenType, &h)) {
        NewToken.attach(h);
        return TRUE;
    }
    return FALSE;
}
 
static BOOL AllocateAndInitializeSid(_In_ PSID_IDENTIFIER_AUTHORITY pIdentifierAuthority, _In_ BYTE nSubAuthorityCount, _In_ DWORD nSubAuthority0, _In_ DWORD nSubAuthority1, _In_ DWORD nSubAuthority2, _In_ DWORD nSubAuthority3, _In_ DWORD nSubAuthority4, _In_ DWORD nSubAuthority5, _In_ DWORD nSubAuthority6, _In_ DWORD nSubAuthority7, _Inout_ winstd::security_id& Sid)
{
    PSID h;
    if (AllocateAndInitializeSid(pIdentifierAuthority, nSubAuthorityCount, nSubAuthority0, nSubAuthority1, nSubAuthority2, nSubAuthority3, nSubAuthority4, nSubAuthority5, nSubAuthority6, nSubAuthority7, &h)) {
        Sid.attach(h);
        return TRUE;
    }
    return FALSE;
}
 
static DWORD SetEntriesInAclA(_In_ ULONG cCountOfExplicitEntries, _In_reads_opt_(cCountOfExplicitEntries) PEXPLICIT_ACCESS_A pListOfExplicitEntries, _In_opt_ PACL OldAcl, _Inout_ std::unique_ptr<ACL, winstd::LocalFree_delete<ACL>>& Acl)
{
    PACL h;
    DWORD dwResult = SetEntriesInAclA(cCountOfExplicitEntries, pListOfExplicitEntries, OldAcl, &h);
    if (dwResult == ERROR_SUCCESS)
        Acl.reset(h);
    return ERROR_SUCCESS;
}
 
static DWORD SetEntriesInAclW(_In_ ULONG cCountOfExplicitEntries, _In_reads_opt_(cCountOfExplicitEntries) PEXPLICIT_ACCESS_W pListOfExplicitEntries, _In_opt_ PACL OldAcl, _Inout_ std::unique_ptr<ACL, winstd::LocalFree_delete<ACL>>& Acl)
{
    PACL h;
    DWORD dwResult = SetEntriesInAclW(cCountOfExplicitEntries, pListOfExplicitEntries, OldAcl, &h);
    if (dwResult == ERROR_SUCCESS)
        Acl.reset(h);
    return ERROR_SUCCESS;
}
 
template<class _Traits, class _Ax>
_Success_(return != 0) BOOL GetThreadPreferredUILanguages(_In_ DWORD dwFlags, _Out_ PULONG pulNumLanguages, _Out_ std::basic_string<wchar_t, _Traits, _Ax> &sValue)
{
    wchar_t szStackBuffer[WINSTD_STACK_BUFFER_BYTES/sizeof(wchar_t)];
    ULONG ulSize = _countof(szStackBuffer);
 
    // Try with stack buffer first.
    if (GetThreadPreferredUILanguages(dwFlags, pulNumLanguages, szStackBuffer, &ulSize)) {
        // Copy from stack.
        sValue.assign(szStackBuffer, ulSize - 1);
        return TRUE;
    } else if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
        // Query required size.
        ulSize = 0;
        GetThreadPreferredUILanguages(dwFlags, pulNumLanguages, NULL, &ulSize);
        // Allocate on heap and retry.
        std::unique_ptr<WCHAR[]> szBuffer(new WCHAR[ulSize]);
        if (GetThreadPreferredUILanguages(dwFlags, pulNumLanguages, szBuffer.get(), &ulSize)) {
            sValue.assign(szBuffer.get(), ulSize - 1);
            return TRUE;
        }
    }
    return FALSE;
}
 
#pragma warning(pop)