libcruft-util/rand/system_linux.hpp

38 lines
985 B
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2019 Danny Robson <danny@nerdcruft.net>
*/
#pragma once
#include "../posix/fd.hpp"
namespace cruft::rand {
/// Models std::random_device and is suitable as a drop-in replacement.
class file {
public:
using result_type = unsigned;
file ();
file (std::string const&);
file (file const &) = delete;
file& operator= (file const&) = delete;
result_type operator() (void);
double entropy (void) const noexcept;
static constexpr result_type min (void) { return std::numeric_limits<result_type>::min (); }
static constexpr result_type max (void) { return std::numeric_limits<result_type>::max (); }
private:
cruft::posix::fd m_fd;
};
using system = file;
}