multiprecision/example/cpp_int_import_export.cpp

44 lines
1.1 KiB
C++

///////////////////////////////////////////////////////////////
// Copyright 2015 John Maddock. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
#include <boost/multiprecision/cpp_int.hpp>
#include <iostream>
#include <iomanip>
#include <vector>
#include <iterator>
//[IE1
/*`
In this simple example, we'll import/export the bits of a cpp_int
to a vector of 8-bit unsigned values:
*/
/*=
#include <boost/multiprecision/cpp_int.hpp>
#include <iostream>
#include <iomanip>
#include <vector>
#include <iterator>
*/
int main()
{
using boost::multiprecision::cpp_int;
// Create a cpp_int with just a couple of bits set:
cpp_int i;
bit_set(i, 5000); // set the 5000'th bit
bit_set(i, 200);
bit_set(i, 50);
// export into 8-bit unsigned values, most significant bit first:
std::vector<unsigned char> v;
export_bits(i, std::back_inserter(v), 8);
// import back again, and check for equality:
cpp_int j;
import_bits(j, v.begin(), v.end());
BOOST_ASSERT(i == j);
}
//]