Struct-pattern.cpp

#include "matchit.h"
#include <iostream>
using namespace matchit;

template <size_t I>
constexpr auto get = [](auto &&pt)
{ return std::get<I>(pt); };

template <size_t I>
constexpr auto appGet = [](auto &&pat)
{ return app(get<I>, pat); };

void sample()
{
  struct Point
  {
    uint32_t x;
    uint32_t y;
  };
  constexpr auto s = Point{1U, 1U};

  match(s)(
      // clang-format off
        pattern | and_(app(&Point::x, 10U), app(&Point::y, 20U)) = []{},
        pattern | and_(app(&Point::y, 10U), app(&Point::x, 20U)) = []{},    // order doesn't matter
        pattern | app(&Point::x, 10U)                            = []{},
        pattern | _                                              = []{} // clang-format on
  );

  using PointTuple = std::tuple<uint32_t, uint32_t>;
  constexpr auto t = PointTuple{1U, 2U};

  match(t)(
      // clang-format off
        pattern | and_(appGet<0>(10U), appGet<1>(20U)) = []{},
        pattern | and_(appGet<1>(10U), appGet<0>(20U)) = []{},   // order doesn't matter
        pattern | appGet<0>(10U)                       = []{},
        pattern | _                                    = []{} // clang-format on
  );
}

int32_t main()
{
  sample();
  return 0;
}