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C++14-Compatible WinReg

I got several requests by people asking to make my C++ WinReg code (which has been using C++17 in its main branch since many months) compile on older C++14 compilers (like VS 2017 in C++14 mode).

Now you can find the C++14-compatible version in this branch.

To make the code C++14-compatible, among other things, I removed the use of [[nodiscard]], removed std::variant (simply substituted with a couple of data members), and replaced the non-const std::wstring::data() method with &s[0].

 

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Open Source: Who Pays for It?

Recently I worked on my C++ WinReg library for a couple of hours, adding some useful methods, testing them, and packaging the library for vcpkg distribution.

At a reasonable rate of $150/hour, that would be $300.

And that’s not even counting all the many hours I spent in total on this open-source project.

This library has currently more than 260 stars on GitHub, and many forks. It seems to me it is used by many people.

But who pays for it?

I think there should be some process to allow developers of useful open-source code hosted on GitHub (or on other platforms as well) to be fairly compensated for their work.

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Simplifying Windows Registry Programming with the C++ WinReg Library

The native Windows Registry API is a C-interface API, that is low-level and kind of hard and cumbersome to use.

For example, suppose that you simply want to read a string value under a given key. You would end up writing code like this:

Sample code excerpt to read a string value from the Windows Registry using the native Windows API.
Sample code excerpt to read a string value from the Windows Registry using the native Windows API.

And this is just the part to query the destination string length. Then, you need to allocate a string object with proper size (and pay attention to proper size-in-bytes-to-size-in-wchar_ts conversion!), and after that you can finally read the actual string value into the local string object.

That’s definitely a lot of bug-prone C++ code, and this is just to query a string value!

Moreover, in modern C++ code you should prefer using nice higher-level resource manager classes with automatic resource cleanup, instead of raw HKEY handles.

Fortunately, it’s possible to hide that kind of complex and bug-prone code in a nice C++ library, that offers a much more programmer-friendly interface. This is basically what my C++ WinReg library does.

You can query a string value with just one simple line of C++ code using WinReg.
You can query a string value with just one simple line of C++ code using WinReg.

WinReg is an open-source C++ library, available on GitHub. For the sake of convenience, I packaged and distribute it as a header-only library, which is also available via the vcpkg package manager.

If you need to access the Windows Registry from your C++ code, you may want to give C++ WinReg a try.

 

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C++ WinReg Update

The Windows Registry native C API is very low-level and hard to use.

A while back I developed some convenient higher-level C++ wrappers, that should make Windows Registry programming easier and more fun. You can find them on GitHub.

Just to give you a taste of this C++ WinReg library, you can simply open a registry key with code like this:

RegKey key{ HKEY_CURRENT_USER, L"SOFTWARE\\MyKey" };

And you can read registry values like that:

DWORD dw = key.GetDwordValue(L"MagicCode");
wstring s = key.GetStringValue(L"ReadMe");

Enumerating values under a given key is as easy as:

auto values = key.EnumValues();

Error management is performed using C++ exceptions (instead of “raw” error codes like in the native C API).

You can find more info in the README file.

I haven’t touched that project in a few months (being very busy), but yesterday I accepted an external contribution and merged a pull request adding a DeleteTree feature.

I take this occasion to thank everyone who showed interest and appreciation for this project.

Happy coding!

 

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C++ Wrappers for Windows Registry APIs

I uploaded on GitHub some C++ code of mine that wraps some Windows registry C-interface APIs, using RAII, STL classes like std::wstring and std::vector, and signals error conditions using exceptions.

Using these high-level C++ wrappers, you can easily access the Windows registry with simple code like this:

// Open a registry key
RegKey key{ 
    HKEY_CURRENT_USER, 
    LR"(SOFTWARE\MyKey\SubKey)" 
};

// Read a DWORD value
DWORD dw = key.GetDwordValue(L"MyValue1");

// Read a string value
wstring s = key.GetStringValue(L"MyValue2");

// Enumerate the values under the given key
auto values = key.EnumValues();

// etc.

On the May issue of MSDN Magazine you’ll find an article describing some of the techniques applied in this code.

EDIT 2017-05-02: Added link to my MSDN Magazine article.