cpp11-range_python_like/test.cpp at master · vn-os/cpp11-range_python_like · GitHub

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#include "range.hpp"

#include <algorithm>

#include <iostream>

#include <iterator>

#include <vector>

template <typename R>

void print_range(R const& range);

template <typename R>

void test_range_size(R const& range);

int main() {

using std::cout;

using util::lang::range;

using util::lang::indices;

cout << "Basic usage: iterating over a range of numbers.\n";

for (auto i : range(1, 5)) {

cout << i << " ";

}

cout << "\n";

cout << "Ranges can be “infinite”.\n";

for (auto u : range(0u)) {

if (u == 3u) {

cout << "\n";

break;

}

cout << u << " ";

}

cout << "Ranges can be non-numeric, as long as the type is incrementable and equality comparable.\n";

print_range(range('a', 'd'));

cout << "Ranges can be non-contiguous.\n";

print_range(range(20u, 29u).step(2u));

cout << "… and we can even step backwards.\n";

for (auto i : range(100).step(-3)) {

if (i < 90) {

cout << "\n";

break;

}

cout << i << " ";

}

cout << "\n";

cout << "Container indices are a special case of ranges.\n";

std::vector<int> x{1, 2, 3};

print_range(indices(x));

print_range(indices({"foo", "bar"}));

cout << "Strings are containers, too.\n";

print_range(indices("foobar").step(2));

cout << "\n";

// TODO: Test cases; do something smarter with them.

print_range(range(6, 10));

print_range(range(1, 8).step(2));

print_range(range(8, 1).step(-2));

print_range(range(8.0, 1.0).step(-2.0));

cout << "\n";

cout << "Mixed type inference:\n";

print_range(range(0, sizeof "Hello"));

cout << "Inferred as mangled type name "

<< typeid(typename std::iterator_traits<decltype(range(0, sizeof "Hello").begin())>::value_type).name()

<< " (expected: " << typeid(decltype(sizeof "Hello")).name() << ")\n";

cout << "\n";

test_range_size(range(1, 8).step(2));

test_range_size(range(8.0, 1.0).step(-2.0));

test_range_size(range(8, 1).step(-2));

test_range_size(range(0.1, 0.11).step(2));

test_range_size(range(-7, 1).step(7));

}

namespace util { namespace lang {

template <typename T>

std::ostream& operator <<(std::ostream& out, step_range_proxy<T> const& r) {

return out << "range(" << *r.begin() << ", " << *r.end() << ")"

<< ".step(" << r.begin().step_ << ")";

}

template <typename T>

std::ostream& operator <<(std::ostream& out, range_proxy<T> const& r) {

return out << "range(" << *r.begin() << ", " << *r.end() << ")";

}

}}

template <typename R>

void print_range(R const& range) {

using T = typename std::iterator_traits<decltype(range.begin())>::value_type;

std::cout << range << " = ";

std::copy(range.begin(), range.end(), std::ostream_iterator<T>(std::cout, " "));

std::cout << "\n";

}

template <typename R>

std::size_t manual_range_size(R const& range) {

std::size_t size = 0;

for (auto const& _ : range) ++size, (void) _;

return size;

}

template <typename R>

void test_range_size(R const& range) {

auto const real_size = manual_range_size(R{range});

if (real_size == range.size()) {

std::cout << range << ".size() = " << real_size << "\n";

} else {

std::cout << "ERROR: " << range << ".size() ≠ " << real_size

<< " (was " << range.size() << ")!\n";

}

cpp11-range_python_like/test.cpp at master · vn-os/cpp11-range_python_like · GitHub

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