//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <random>
// template <class UIntType, size_t w, size_t n, size_t m, size_t r,
// UIntType a, size_t u, UIntType d, size_t s,
// UIntType b, size_t t,
// UIntType c, size_t l, UIntType f>
// class mersenne_twister_engine;
// template <class Sseq> explicit mersenne_twister_engine(Sseq &q);
//
// [ ... ] Finally, if the most significant $w-r$ bits of $X_{-n}$ are zero,
// and if each of the other resulting $X_i$ is $0$, changes $X_{-n}$ to
// $ 2^{w-1} $.
#include <random>
#include <algorithm>
#include <cassert>
#include <cstddef>
#include "test_macros.h"
struct all_zero_seed_seq {
typedef unsigned int result_type;
all_zero_seed_seq() {}
template <typename InputIterator>
all_zero_seed_seq(InputIterator, InputIterator) {}
#if TEST_STD_VER >= 11
all_zero_seed_seq(std::initializer_list<result_type>) {}
#endif
template <typename RandomAccessIterator>
void generate(RandomAccessIterator rb, RandomAccessIterator re) {
std::fill(rb, re, 0u);
}
std::size_t size() const { return 0u; }
template <typename OutputIterator> void param(OutputIterator) const {}
};
template <typename result_type, std::size_t word_size>
void test(void) {
const std::size_t state_size = 1u;
const std::size_t shift_size = 1u;
const std::size_t tempering_l = word_size;
all_zero_seed_seq q;
std::mersenne_twister_engine<result_type, word_size, state_size,
shift_size,
0u,
0x0,
0u, 0x0, 0u, 0x0, 0u, 0x0,
tempering_l,
0u>
e(q);
const result_type Xneg1 = result_type(1) << (word_size - 1);
const result_type Y = Xneg1;
const result_type X0 = Xneg1 ^ (Y >> 1);
assert(e() == X0);
}
int main(int, char**) {
// Test for k == 1: word_size <= 32.
test<unsigned short, 3u>();
// Test for k == 2: (32 < word_size <= 64).
test<unsigned long long, 33u>();
return 0;
}