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// Range v3 library
//
// Copyright 2019 Christopher Di Bella
//
// Use, modification and distribution is subject to the
// Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ericniebler/range-v3
#include <range/v3/algorithm/starts_with.hpp>
#include "../simple_test.hpp"
#include "../test_iterators.hpp"
#include <forward_list>
#include <range/v3/range/conversion.hpp>
#include <range/v3/view/iota.hpp>
#include <range/v3/view/slice.hpp>
#include <range/v3/view/take_exactly.hpp>
#include <range/v3/view/istream.hpp>
#include <sstream>
#include <vector>
void test_defaults()
{
using namespace ranges;
{ // checks starts_with works for input ranges
constexpr auto full_latin_alphabet = "a b c d e f g h i j k l m n o p q r s t u v w x y z";
auto const partial_latin_alphabet = "a b c d";
{
auto long_stream = std::istringstream{full_latin_alphabet};
auto short_stream = std::istringstream{partial_latin_alphabet};
auto r1 = istream<char>(long_stream);
auto r2 = istream<char>(short_stream);
CHECK(starts_with(begin(r1), end(r1), begin(r2), end(r2)));
}
{
auto long_stream = std::istringstream{full_latin_alphabet};
auto short_stream = std::istringstream{partial_latin_alphabet};
auto r1 = istream<char>(long_stream);
auto r2 = istream<char>(short_stream);
CHECK(!starts_with(begin(r2), end(r2), begin(r1), end(r1)));
}
{
auto long_stream = std::istringstream{full_latin_alphabet};
auto short_stream = std::istringstream{partial_latin_alphabet};
CHECK(starts_with(istream<char>(long_stream), istream<char>(short_stream)));
}
{
auto long_stream = std::istringstream{full_latin_alphabet};
auto short_stream = std::istringstream{partial_latin_alphabet};
CHECK(!starts_with(istream<char>(short_stream), istream<char>(long_stream)));
}
}
{ // checks starts_with works for random-access ranges
#ifdef RANGES_WORKAROUND_MSVC_779708
auto const long_range = views::iota(0, 100) | to<std::vector>();
auto const short_range = views::iota(0, 10) | to<std::vector>();
#else // ^^^ workaround / no workaround vvv
auto const long_range = views::iota(0, 100) | to<std::vector>;
auto const short_range = views::iota(0, 10) | to<std::vector>;
#endif // RANGES_WORKAROUND_MSVC_779708
CHECK(starts_with(begin(long_range), end(long_range), begin(short_range), end(short_range)));
CHECK(starts_with(long_range, short_range));
CHECK(!starts_with(begin(short_range), end(short_range), begin(long_range), end(long_range)));
CHECK(!starts_with(short_range, long_range));
}
{ // checks starts_with works for random-access ranges with arbitrary sentinels
auto const long_range = views::iota(0);
auto const short_range = views::iota(0) | views::take_exactly(100);
CHECK(starts_with(begin(long_range), end(long_range), begin(short_range), end(short_range)));
CHECK(starts_with(long_range, short_range));
CHECK(!starts_with(begin(short_range), end(short_range), begin(long_range), end(long_range)));
CHECK(!starts_with(short_range, long_range));
}
{ // checks starts_with identifies a subrange
auto const range = views::iota(0) | views::slice(50, 100);
auto const offset = views::iota(50, 100);
CHECK(starts_with(begin(range), end(range), begin(offset), end(offset)));
CHECK(starts_with(range, offset));
CHECK(starts_with(begin(offset), end(offset), begin(range), end(range)));
CHECK(starts_with(offset, range));
}
{ // checks starts_with identifies when two ranges don't have the same start sequence
auto const first = views::iota(0, 1'000);
auto const second = views::iota(10, 1'000);
CHECK(!starts_with(begin(first), end(first), begin(second), end(second)));
CHECK(!starts_with(first, second));
CHECK(!starts_with(begin(second), end(second), begin(first), end(first)));
CHECK(!starts_with(second, first));
}
}
void test_comparison()
{
using namespace ranges;
auto const long_range = views::iota(0, 100);
auto const short_range = views::iota(1, 51);
CHECK(starts_with(begin(long_range), end(long_range), begin(short_range), end(short_range),
less{}));
CHECK(starts_with(long_range, short_range, less{}));
CHECK(!starts_with(begin(long_range), end(long_range), begin(short_range), end(short_range),
greater{}));
CHECK(!starts_with(long_range, short_range, greater{}));
}
int main()
{
::test_defaults();
::test_comparison();
return ::test_result();
}
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