#include "helpers.hpp"

#include <count.hpp>

#include <vector>

#include <iterator>

#include <utility>

#include "catch.hpp"

using iter::count;

TEST_CASE("count: watch for 10 elements", "[count]") {

std::vector<int> v{};

for (auto i : count()) {

v.push_back(i);

if (i == 9) break;

}

const std::vector<int> vc{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

REQUIRE(v == vc);

}

TEST_CASE("count: start at 10", "[count]") {

std::vector<int> v{};

for (auto i : count(10)) {

v.push_back(i);

if (i == 14) break;

}

const std::vector<int> vc{10, 11, 12, 13, 14};

REQUIRE(v == vc);

}

TEST_CASE("count: with step", "[count]") {

std::vector<int> v{};

for (auto i : count(2, -1)) {

v.push_back(i);

if (i == -3) break;

}

const std::vector<int> vc{2, 1, 0, -1, -2, -3};

REQUIRE(v == vc);

}

TEST_CASE("count: with step > 1", "[count]") {

std::vector<int> v{};

for (auto i : count(10, 2)) {

v.push_back(i);

if (i == 16) break;

}

const std::vector<int> vc{10, 12, 14, 16};

REQUIRE(v == vc);

}

TEST_CASE("count: can bo constexpr", "[count]") {

constexpr auto c = count();

constexpr auto c2 = count(5);

(void)c2;

constexpr auto c3 = count(5, 2);

(void)c3;

constexpr auto it = c.begin();

constexpr auto i = *it;

static_assert(i == 0, "count begin not correct value");

}

TEST_CASE("count: iterator meets requirements", "[count]") {

auto c = count();

REQUIRE(itertest::IsIterator<decltype(std::begin(c))>::value);

}