Identifier-pattern.cpp

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

void sample1()
{
  constexpr auto x = 2;
  Id<int32_t> e;
  match(x)(
      // clang-format off
        pattern | e.at(1 <= _ && _ <= 5) = [&] { std::cout << "got a range element " << *e << std::endl; },
        pattern | _                      = [&] { std::cout << "anything" << std::endl; }
      // clang-format on
  );
}

struct Person
{
  std::string name;
  uint8_t age;
};

auto const name_age = dsVia(&Person::name, &Person::age);

void sample2()
{
  auto const value = Person{"John", 23};
  Id<std::string> person_name;
  match(value)(pattern | name_age(person_name, 18 <= _ && _ <= 150) = [] {});
}
void sample3()
{
  constexpr auto x = std::make_optional(3);
  Id<int32_t> y;
  match(x)(
      // No need to worry about y's type, by ref or by value is automatically
      // managed by `match(it)` library.
      pattern | some(y) = [] {});
}

void sample4()
{
  Id<std::string> person_name;
  Id<uint8_t> age;
  auto value = Person{"John", 23};
  match(std::move(value))(
      // `name` is moved from person and `age` copied (scalar types are copied
      // in `match(it)`)
      pattern | name_age(person_name, age) = [] {});
}

int32_t main()
{
  sample1();
  sample2();
  sample3();
  return 0;
}