by Giovanni Dicanio
The Windows Registry C-interface API is very low-level and hard to use.
I developed some C++ wrappers around this low-level Win32 API, to raise the semantic level, using C++ classes like std::wstring, std::vector, etc. instead of raw C-style buffers and low-level mechanisms.
For example, the REG_MULTI_SZ registry type associated to double-NUL-terminated C-style strings is handled using a much easier higher-level vector<wstring>. My C++ code does the translation between high-level C++ STL-based stuff and low-level Win32 C-interface APIs.
Moreover, Win32 error codes are translated to C++ exceptions.
The Win32 registry value types are mapped to C++ higher-level types according the following table:
| Win32 Registry Type | C++ Type |
|---|---|
REG_DWORD |
DWORD |
REG_QWORD |
ULONGLONG |
REG_SZ |
std::wstring |
REG_EXPAND_SZ |
std::wstring |
REG_MULTI_SZ |
std::vector<std::wstring> |
REG_BINARY |
std::vector<BYTE> |
I developed this code using Visual Studio 2015 with Update 3. The code compiles cleanly at /W4 in both 32-bit and 64-bit builds.
The library's code is contained in a reusable header-only WinReg.hpp file.
WinRegTest.cpp contains some demo/test code for the library: check it out for some sample usage.
The library exposes two main classes:
RegKey: a tiny efficient wrapper around raw Win32HKEYhandlesRegException: an exception class to signal error conditions
There are many member functions inside the RegKey class, that wrap raw Win32 registry C-interface APIs
in a convenient C++ way.
For example, you can simply open a registry key and get registry values with C++ code like this:
RegKey key{ HKEY_CURRENT_USER, L"SOFTWARE\\Connie" };
DWORD dw = key.GetDwordValue(L"SomeDwordValue");
wstring s = key.GetStringValue(L"SomeStringValue");Or you can enumerate all the values under a key with this simple code:
auto values = key.EnumValues();The library stuff lives under the winreg namespace.
See the WinReg.hpp header for more details and documentation.