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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// <algorithm>
// template<RandomAccessIterator Iter, StrictWeakOrder<auto, Iter::value_type> Compare>
// requires ShuffleIterator<Iter>
// && CopyConstructible<Compare>
// void
// partial_sort(Iter first, Iter middle, Iter last, Compare comp);
#include <algorithm>
#include <vector>
#include <functional>
#include <random>
#include <cassert>
#include <cstddef>
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
#include <memory>
struct indirect_less
{
template <class P>
bool operator()(const P& x, const P& y)
{return *x < *y;}
};
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
std::mt19937 randomness;
void
test_larger_sorts(int N, int M)
{
assert(N != 0);
assert(N >= M);
int* array = new int[N];
for (int i = 0; i < N; ++i)
array[i] = i;
std::shuffle(array, array+N, randomness);
std::partial_sort(array, array+M, array+N, std::greater<int>());
for (int i = 0; i < M; ++i)
{
assert(i < N); // quiet analysis warnings
assert(array[i] == N-i-1);
}
delete [] array;
}
void
test_larger_sorts(int N)
{
test_larger_sorts(N, 0);
test_larger_sorts(N, 1);
test_larger_sorts(N, 2);
test_larger_sorts(N, 3);
test_larger_sorts(N, N/2-1);
test_larger_sorts(N, N/2);
test_larger_sorts(N, N/2+1);
test_larger_sorts(N, N-2);
test_larger_sorts(N, N-1);
test_larger_sorts(N, N);
}
int main()
{
{
int i = 0;
std::partial_sort(&i, &i, &i);
assert(i == 0);
test_larger_sorts(10);
test_larger_sorts(256);
test_larger_sorts(257);
test_larger_sorts(499);
test_larger_sorts(500);
test_larger_sorts(997);
test_larger_sorts(1000);
test_larger_sorts(1009);
}
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
{
std::vector<std::unique_ptr<int> > v(1000);
for (int i = 0; static_cast<std::size_t>(i) < v.size(); ++i)
v[i].reset(new int(i));
std::partial_sort(v.begin(), v.begin() + v.size()/2, v.end(), indirect_less());
for (int i = 0; static_cast<std::size_t>(i) < v.size()/2; ++i)
assert(*v[i] == i);
}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
}
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