WSJT-X/boost/libs/numeric/interval/examples/io.cpp

173 lines
4.9 KiB
C++

/* Boost examples/io.cpp
* show some exampleso of i/o operators
* thanks to all the people who commented on this point, particularly on
* the Boost mailing-list
*
* Copyright 2003 Guillaume Melquiond
*
* Distributed under the Boost Software License, Version 1.0.
* (See accompanying file LICENSE_1_0.txt or
* copy at http://www.boost.org/LICENSE_1_0.txt)
*/
#include <boost/numeric/interval.hpp>
#include <boost/io/ios_state.hpp>
#include <cmath>
#include <cassert>
namespace io_std {
template<class T, class Policies, class CharType, class CharTraits>
std::basic_ostream<CharType, CharTraits> &operator<<
(std::basic_ostream<CharType, CharTraits> &stream,
const boost::numeric::interval<T, Policies> &value)
{
if (empty(value)) {
return stream << "[]";
} else {
return stream << '[' << lower(value) << ',' << upper(value) << ']';
}
}
} // namespace io_std
namespace io_sngl {
template<class T, class Policies, class CharType, class CharTraits>
std::basic_ostream<CharType, CharTraits> &operator<<
(std::basic_ostream<CharType, CharTraits> &stream,
const boost::numeric::interval<T, Policies> &value)
{
if (empty(value)) {
return stream << "[]";
} else if (singleton(value)) {
return stream << '[' << lower(value) << ']';
} else {
return stream << '[' << lower(value) << ',' << upper(value) << ']';
}
}
} // namespace io_sngl
namespace io_wdth {
template<class T, class Policies, class CharType, class CharTraits>
std::basic_ostream<CharType, CharTraits> &operator<<
(std::basic_ostream<CharType, CharTraits> &stream,
const boost::numeric::interval<T, Policies> &value)
{
if (empty(value)) {
return stream << "nothing";
} else {
return stream << median(value) << " ± " << width(value) / 2;
}
}
} // namespace io_wdth
namespace io_prec {
template<class T, class Policies, class CharType, class CharTraits>
std::basic_ostream<CharType, CharTraits> &operator<<
(std::basic_ostream<CharType, CharTraits> &stream,
const boost::numeric::interval<T, Policies> &value)
{
if (empty(value)) {
return stream << "nothing";
} else if (singleton(value)) {
boost::io::ios_precision_saver state(stream, std::numeric_limits<T>::digits10);
return stream << lower(value);
} else if (zero_in(value)) {
return stream << "0~";
} else {
const T rel = width(value) / norm(value);
int range = - (int)std::log10(rel);
boost::io::ios_precision_saver state(stream, range);
return stream << median(value);
}
}
} // namespace io_prec
namespace io_wide {
template<class T, class Policies, class CharType, class CharTraits>
std::basic_ostream<CharType, CharTraits> &operator<<
(std::basic_ostream<CharType, CharTraits> &stream,
const boost::numeric::interval<T, Policies> &value)
{
if (empty(value)) {
return stream << "nothing";
} else if (singleton(value)) {
boost::io::ios_precision_saver state(stream, std::numeric_limits<T>::digits10);
return stream << lower(value);
} else if (zero_in(value)) {
return stream << "0~";
} else {
std::streamsize p = stream.precision();
// FIXME poor man's power of 10, only up to 1E-15
p = (p > 15) ? 15 : p - 1;
double eps = 1.0; for(; p > 0; --p) { eps /= 10; }
T eps2 = static_cast<T>(eps / 2) * norm(value);
boost::numeric::interval<T, Policies> r = widen(value, eps2);
return stream << '[' << lower(r) << ',' << upper(r) << ']';
}
}
} // namespace io_wide
template<class T, class Policies, class CharType, class CharTraits> inline
std::basic_istream<CharType, CharTraits> &operator>>
(std::basic_istream<CharType, CharTraits> &stream,
boost::numeric::interval<T, Policies> &value)
{
T l, u;
char c = 0;
stream >> c;
if (c == '[') {
stream >> l >> c;
if (c == ',') stream >> u >> c; else u = l;
if (c != ']') stream.setstate(stream.failbit);
} else {
stream.putback(c);
stream >> l;
u = l;
}
if (stream)
value.assign(l, u);
else
value = boost::numeric::interval<T, Policies>::empty();
return stream;
}
// Test program
#include <iostream>
int main()
{
using namespace boost;
using namespace numeric;
using namespace interval_lib;
typedef interval<double,
policies<rounded_math<double>,
checking_base<double> > > I;
I tab[] = { I::empty(), I(1,1), I(1,2), I(-1,1), I(12.34,12.35),
I(1234.56,1234.57), I(123456.78, 123456.79), I::empty() };
unsigned int len = sizeof(tab) / sizeof(I);
std::cout << "Enter an interval: (it will be the last shown)\n";
std::cin >> tab[len - 1];
for(unsigned int i = 0; i < len; ++i) {
{ using namespace io_std; std::cout << tab[i] << '\n'; }
{ using namespace io_sngl; std::cout << tab[i] << '\n'; }
{ using namespace io_wdth; std::cout << tab[i] << '\n'; }
{ using namespace io_prec; std::cout << tab[i] << '\n'; }
{ using namespace io_wide; std::cout << tab[i] << '\n'; }
std::cout << '\n';
}
}