WinReg v1.2.1

High-level C++ Wrapper Around the Low-level Windows Registry C-interface API

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 the low-level Win32 C-interface API.

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 Win32 HKEY handles
RegException: an exception class to signal error conditions

There are many member functions inside the RegKey class, that wrap many parts of the native C-interface Windows Registry API, 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\\SomeKey" };

DWORD   dw = key.GetDwordValue (L"SomeDwordValue");
wstring s  = key.GetStringValue(L"SomeStringValue");

Or you can enumerate all the values under a given key with simple C++ code like this:

auto values = key.EnumValues();

for (const auto & v : values)
{
    //
    // Process current value:
    //
    //   - v.first  (wstring) is the value name
    //   - v.second (DWORD)   is the value type
    //
    ...
}

The library stuff lives under the winreg namespace.

See the WinReg.hpp header for more details and documentation.

For those who use the vcpkg package manager, this library was also added to the vcpkg catalog.

Thanks to everyone who contributed to this project with some additional features and constructive comments and suggestions.

dongzhaosheng73/WinReg

WinReg v1.2.1

High-level C++ Wrapper Around the Low-level Windows Registry C-interface API