boost::numeric::interval<int>(0): C++ Boost 区間演算ライブラリ 概要 ref: http://qiita.com/items/7712671389e016d24df6

file1.txt

$ g++ hello-interval.cpp -o hello-interval
$ ./hello-interval
[-1,2]

file3.txt

$ g++ test-interval-double.cpp -o test-interval-double
$ ./test-interval-double
eps = 1e-14
one = [1,1]
x = one + eps - one = [9.99201e-15,1.02141e-14]
width(x) = 2.22045e-16
eps is in x

file4.txt

$ clang++ test-interval-double.cpp -o test-interval-double
$ ./test-interval-double
eps = 1e-14
one = [1,1]
x = one + eps - one = [9.99201e-15,9.99201e-15]
width(x) = 0
eps is not in x

hello-interval.cpp

#include <iostream>
#include <boost/numeric/interval.hpp>
#include <boost/numeric/interval/io.hpp>

int main () {
    boost::numeric::interval<int> a(-1, 2);
    std::cout << a << std::endl;
    return 0;
}

test-interval-double.cpp

#include <iostream>
#include <boost/numeric/interval.hpp>
#include <boost/numeric/interval/io.hpp>

int main () {
    using namespace std;
    using namespace boost::numeric;
    typedef double R;
    typedef interval<R> IR;
    const R eps(1.0e-14);
    const IR one(1.0);
    const IR x = one + eps - one;
    cout << "eps = " << eps << endl;
    cout << "one = " << one << endl;
    cout << "x = one + eps - one = " << x << endl;
    cout << "width(x) = " << width(x) << endl;
    cout << "eps is " << (in(eps, x) ? "" : "not ") << "in x" << endl;
    return 0;
}