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// Copyright (C) 2018-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
// { dg-do run { target c++11 } }
// { dg-require-cstdint "" }
#include <random>
#include <testsuite_hooks.h>
template<typename T>
struct seed_seq
{
using result_type = unsigned;
seed_seq() { }
template<class U>
seed_seq(std::initializer_list<U>) { }
template<class InputIterator>
seed_seq(InputIterator, InputIterator) { }
template<class RandomAccessIterator>
void generate(RandomAccessIterator first, RandomAccessIterator last)
{
called = true;
if (first != last)
*first = 42;
}
size_t size() const { called = true; return 1; }
template<class OutputIterator>
void param(OutputIterator dest) const { called = true; dest = 42; }
// Prevents this type being considered as a seed sequence when
// T is convertible to the engine's result_type:
operator T() const noexcept { return T(); }
bool called = false;
};
using engine_type
= std::mersenne_twister_engine<
unsigned long, 32, 624, 397, 31,
0x9908b0dful, 11,
0xfffffffful, 7,
0x9d2c5680ul, 15,
0xefc60000ul, 18, 1812433253ul>;
void
test01()
{
seed_seq<unsigned> seed;
engine_type x(seed);
VERIFY( ! seed.called );
}
void
test02()
{
seed_seq<void*> seed;
engine_type x(seed);
VERIFY( seed.called );
static_assert(!std::is_constructible<engine_type, const seed_seq<void>&>(),
"Cannot construct from a const seed_seq");
}
int main()
{
test01();
test02();
}
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