Helpers.h

// <copyright file="Helpers.h" company="Microsoft Corporation">
// Copyright (C) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license. See LICENSE.txt in the project root for license information.
// </copyright>

#pragma once

#define __nameof(x) L#x

#define FALSESTRING L"False"
#define TRUESTRING L"True"

struct ModuleDeleter
{
    void operator()(_In_ HMODULE* phModule)
    {
        if (phModule && *phModule)
        {
            ::FreeLibrary(*phModule);
        }
    }
};

typedef std::unique_ptr<HMODULE, ModuleDeleter> module_ptr;

struct SafeArrayDeleter
{
    void operator()(_In_ LPSAFEARRAY* ppsa)
    {
        if (ppsa && *ppsa)
        {
            if ((*ppsa)->cLocks)
            {
                ::SafeArrayUnlock(*ppsa);
            }

            ::SafeArrayDestroy(*ppsa);
        }
    }
};

typedef std::unique_ptr<LPSAFEARRAY, SafeArrayDeleter> safearray_ptr;

class win32_exception :
    public std::exception
{
public:
    win32_exception(_In_ DWORD code, _In_z_ const char* what) noexcept :
        std::exception(what),
        m_code(code)
    {
    }

    win32_exception(_In_ const win32_exception& obj) noexcept :
        std::exception(obj)
    {
        m_code = obj.m_code;
    }

    DWORD code() const noexcept
    {
        return m_code;
    }

private:
    DWORD m_code;
};

class CoInitializer
{
public:
    CoInitializer()
    {
        hr = ::CoInitialize(nullptr);
        if (FAILED(hr))
        {
            throw win32_exception(hr, "failed to initialize COM");
        }
    }

    ~CoInitializer()
    {
        if (SUCCEEDED(hr))
        {
            ::CoUninitialize();
        }
    }

private:
    HRESULT hr;
};

std::wostream& operator<<(_In_ std::wostream& os, _In_ const variant_t& var);