ceph/src/boost/libs/multiprecision/example/mpfi_snips.cpp

   1 ///////////////////////////////////////////////////////////////
   2 //  Copyright 2011 John Maddock. Distributed under the Boost
   3 //  Software License, Version 1.0. (See accompanying file
   4 //  LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
   5
   6 //[mpfi_eg
   7 #include <boost/multiprecision/mpfi.hpp>
   8 #include <boost/math/special_functions/gamma.hpp>
   9 #include <iostream>
  10
  11 int main()
  12 {
  13    using namespace boost::multiprecision;
  14
  15    // Operations at variable precision and no numeric_limits support:
  16    mpfi_float a = 2;
  17    mpfi_float::default_precision(1000);
  18    std::cout << mpfi_float::default_precision() << std::endl;
  19    std::cout << sqrt(a) << std::endl; // print root-2
  20
  21    // Operations at fixed precision and full numeric_limits support:
  22    mpfi_float_100 b = 2;
  23    std::cout << std::numeric_limits<mpfi_float_100>::digits << std::endl;
  24    // We can use any C++ std lib function:
  25    std::cout << log(b) << std::endl; // print log(2)
  26
  27    // Access the underlying data:
  28    mpfi_t r;
  29    mpfi_init(r);
  30    mpfi_set(r, b.backend().data());
  31
  32    // Construct some explicit intervals and perform set operations:
  33    mpfi_float_50 i1(1, 2), i2(1.5, 2.5);
  34    std::cout << intersect(i1, i2) << std::endl;
  35    std::cout << hull(i1, i2) << std::endl;
  36    std::cout << overlap(i1, i2) << std::endl;
  37    std::cout << subset(i1, i2) << std::endl;
  38    mpfi_clear(r);
  39    return 0;
  40 }
  41 //]
  42