https://github.com/avakar/destructure

Structure to Tuple Conversions in C++17
https://github.com/avakar/destructure

cpp cpp17

Last synced: about 2 months ago
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Structure to Tuple Conversions in C++17

• Host: GitHub
• URL: https://github.com/avakar/destructure
• Owner: avakar
• License: mit
• Created: 2019-12-01T22:26:57.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2019-12-06T18:52:42.000Z (over 5 years ago)
• Last Synced: 2025-03-22T15:02:21.524Z (2 months ago)
• Topics: cpp, cpp17
• Language: C++
• Homepage:
• Size: 5.86 KB
• Stars: 25
• Watchers: 2
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Structure to Tuple Conversions in C++17

This single-header library provides the following pair of functions.

    template 

    auto destructure(T & val)

    {

        auto && [an...] = std::forward(val);

        return std::tie(an...);

    }

    template 

    auto destructure(T && val)

    {

        auto && [an...] = std::forward(val);

        return std::tuple(std::move(an)...);

    }

Unfortunately, there are no variadic structured bindings in C++17,

so the implementation is a bit more involved.

## Getting Started

Either use the CMakeFile in the repo or simply copy `destructure.h`

to your project. Then include it.

    #include 

    using avakar::destructure;

Now, consider the following structure.

    struct X

    {

        int a;

        std::string b;

    };

The `destructure` function will turn an object of type `X` into a tuple

of `int` and `std::string`.

    X x;

    auto tied = destructure(x);

    static_assert(std::is_same_v>);

Notice that for an l-value, destructuring results in a tuple

of references. You can modify the object `x` via the tuple.

    std::get<0>(tied) = 1;

    assert(x.a == 1);

For an r-value, `destructure` returns a tuple of values.

    auto tup = destructure(X{1, "test"});

    static_assert(std::is_same_v>);

## Limitations

The library only supports structures of up to 64 members by default,

although you can generate your own version of the header with

the following command.

    ./src/generate.py -n 100

This will output a new header file containing the function

in the `destructure_100` namespace. Use `--inline` to make the namespace

inline.