diff options
| -rw-r--r-- | include/systools/win32/comtools.hxx | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/include/systools/win32/comtools.hxx b/include/systools/win32/comtools.hxx index 8f2d94027952..a675ed2dc6d9 100644 --- a/include/systools/win32/comtools.hxx +++ b/include/systools/win32/comtools.hxx @@ -21,6 +21,7 @@ #define INCLUDED_SYSTOOLS_WIN32_COMTOOLS_HXX #include <string> +#include <string_view> #include <stdexcept> #include <type_traits> #include <objbase.h> @@ -49,6 +50,36 @@ namespace systools HRESULT hr_; }; + /* Convert failed HRESULT to thrown ComError */ + inline void ThrowIfFailed(HRESULT hr, std::string_view msg) + { + if (FAILED(hr)) + throw ComError(std::string(msg), hr); + } + /* A guard class to call CoInitializeEx/CoUninitialize in proper pairs + * See also: o3tl::safeCoInitializeEx doing dangerous re-initialization + */ + class CoInitializeGuard + { + public: + explicit CoInitializeGuard(DWORD dwCoInit, bool bThrowOnChangeMode = false) + { + HRESULT hr = ::CoInitializeEx(nullptr, dwCoInit); + if (FAILED(hr) && (bThrowOnChangeMode || hr != RPC_E_CHANGED_MODE)) + throw ComError("CoInitializeEx failed", hr); + mbUninit = SUCCEEDED(hr); + } + CoInitializeGuard(const CoInitializeGuard&) = delete; // non-construction-copyable + void operator=(const CoInitializeGuard&) = delete; // non-copyable + ~CoInitializeGuard() + { + if (mbUninit) + CoUninitialize(); + } + private: + bool mbUninit; + }; + struct COM_QUERY_TAG {} constexpr COM_QUERY; struct COM_QUERY_THROW_TAG {} constexpr COM_QUERY_THROW; template <typename TAG> @@ -118,7 +149,7 @@ namespace systools COMReference<T2> QueryInterface(TAG) const { void* ip = nullptr; - HRESULT hr = E_FAIL; + HRESULT hr = E_POINTER; if (com_ptr_) hr = com_ptr_->QueryInterface(__uuidof(T2), &ip); if constexpr (std::is_same_v<TAG, COM_QUERY_THROW_TAG>) |