hipony / enumerate Goto Github PK

for (auto&& [index, value] : enumerate(vec, size)) {}

enumerate(aggregate).each([](auto index, auto& value) {
    ...
});

for (auto&& [index, value] : enumerate({0, 1, 2, 3, 4, 5}) {}

for (auto&& [index, value] : enumerate(vec.begin(), vec.end()) {}

template<typename Self>
concept range = requires(Self& self)
{
    ranges::begin(self);
    ranges::end(self);
};

template<typename Self>
concept __member_begin = requires(Self& self)
{
    {self.begin()} -> input_or_output_iterator;
};

struct iter
{
    using difference_type = std::ptrdiff_t;

    iter() = default;
    iter& operator++() {}
    /*any type*/ auto operator++(int) {}
    /*non-void*/ int& operator*() {}
    bool operator==(const iter& other) const {} // automatically matching operator!=
};
static_assert(std::weakly_incrementable<iter>);

struct collection
{
    auto begin() { return iter{}; }
    auto end() { return iter{}; }
};
static_assert(std::ranges::range<collection>);

#define HIPONY_ENUMERATE_HAS_NODISCARD HIPONY_ENUMERATE_CPP17_OR_GREATER

for (auto&& [index, value] : enumerate(container, &Item::member)) {}