hresult_exception.h

#pragma once

#include <atlexcept.h>

class hresult_exception
    : public std::exception {

public:
    HRESULT hr;

    char function[255];

    hresult_exception(const HRESULT& _hr = S_OK, const char _function[] = "none")
        : hr(_hr) {
        strcpy_s(function, 255, _function);
    }

    const char *what() const {
        return "HRESULT exception";
    }
};

template<bool ThrowException>
struct HResultChecker {
    static bool Check(HRESULT _hr);
};

template<> struct HResultChecker<false> {
    static bool Check(const HRESULT& _hr) {
        _hr;
        return true;
    }
};

template<> struct HResultChecker<true> {
    static bool Check(const HRESULT& _hr) {
        if(FAILED(_hr)) {
            throw std::exception("HResult exception");
            return false;
        }
        return true;
    }
};

template<bool ThrowException>
class HResultT {

protected:
    HRESULT hr;

    char function[255];

    std::basic_string<WCHAR> desc;

protected:
    void Assign(const HRESULT& _hr) {
        WORD code = HRESULT_CODE(_hr);
        WORD facility = HRESULT_FACILITY(_hr);
        DWORD severity = HRESULT_SEVERITY(_hr);
        if (!HResultChecker<ThrowException>::Check(hr = _hr))
            throw hresult_exception(hr, function);
    }

public:
    HResultT(const HRESULT& _hr = S_OK, const char _function[] = "none")
        : hr(_hr) {
        strcpy_s(function, 255, _function);
        Assign(hr);
    }

    HResultT& operator() (const char _function[] = "none") {
        strcpy_s(function, 255, _function);
        return *this;
    }

    HResultT& operator() (const HRESULT& _hr, const char _function[] = "none") {
        strcpy_s(function, 255, _function);
        Assign(_hr);
        return *this;
    }

    HResultT& operator= (const HRESULT& _hr) {
        Assign(_hr);
        return *this;
    }
    LPCTSTR ErrrorMessage() const {
        return L"Error";
    }

    operator HRESULT () const {
        return hr;
    }
};

typedef HResultT<true> HResult;

typedef HResultT<false> HResultSafe;