1 | // rational number example program ----------------------------------------// |
2 | |
3 | // (C) Copyright Paul Moore 1999. Permission to copy, use, modify, sell |
4 | // and distribute this software is granted provided this copyright notice |
5 | // appears in all copies. This software is provided "as is" without express or |
6 | // implied warranty, and with no claim as to its suitability for any purpose. |
7 | |
8 | // boostinspect:nolicense (don't complain about the lack of a Boost license) |
9 | // (Paul Moore hasn't been in contact for years, so there's no way to change the |
10 | // license.) |
11 | |
12 | // Revision History |
13 | // 14 Dec 99 Initial version |
14 | |
15 | #include <iostream> |
16 | #include <cassert> |
17 | #include <cstdlib> |
18 | #include <boost/config.hpp> |
19 | #ifndef BOOST_NO_LIMITS |
20 | #include <limits> |
21 | #else |
22 | #include <limits.h> |
23 | #endif |
24 | #include <exception> |
25 | #include <boost/rational.hpp> |
26 | |
27 | using std::cout; |
28 | using std::endl; |
29 | using boost::rational; |
30 | |
31 | #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP |
32 | // This is a nasty hack, required because MSVC does not implement "Koenig |
33 | // Lookup". Basically, if I call abs(r), the C++ standard says that the |
34 | // compiler should look for a definition of abs in the namespace which |
35 | // contains r's class (in this case boost) - among other places. |
36 | |
37 | // Koenig Lookup is a relatively recent feature, and other compilers may not |
38 | // implement it yet. If so, try including this line. |
39 | |
40 | using boost::abs; |
41 | #endif |
42 | |
43 | int main () |
44 | { |
45 | rational<int> half(1,2); |
46 | rational<int> one(1); |
47 | rational<int> two(2); |
48 | |
49 | // Some basic checks |
50 | assert(half.numerator() == 1); |
51 | assert(half.denominator() == 2); |
52 | assert(boost::rational_cast<double>(half) == 0.5); |
53 | |
54 | // Arithmetic |
55 | assert(half + half == one); |
56 | assert(one - half == half); |
57 | assert(two * half == one); |
58 | assert(one / half == two); |
59 | |
60 | // With conversions to integer |
61 | assert(half+half == 1); |
62 | assert(2 * half == one); |
63 | assert(2 * half == 1); |
64 | assert(one / half == 2); |
65 | assert(1 / half == 2); |
66 | |
67 | // Sign handling |
68 | rational<int> minus_half(-1,2); |
69 | assert(-half == minus_half); |
70 | assert(abs(minus_half) == half); |
71 | |
72 | // Do we avoid overflow? |
73 | #ifndef BOOST_NO_LIMITS |
74 | int maxint = (std::numeric_limits<int>::max)(); |
75 | #else |
76 | int maxint = INT_MAX; |
77 | #endif |
78 | rational<int> big(maxint, 2); |
79 | assert(2 * big == maxint); |
80 | |
81 | // Print some of the above results |
82 | cout << half << "+" << half << "=" << one << endl; |
83 | cout << one << "-" << half << "=" << half << endl; |
84 | cout << two << "*" << half << "=" << one << endl; |
85 | cout << one << "/" << half << "=" << two << endl; |
86 | cout << "abs(" << minus_half << ")=" << half << endl; |
87 | cout << "2 * " << big << "=" << maxint |
88 | << " (rational: " << rational<int>(maxint) << ")" << endl; |
89 | |
90 | // Some extras |
91 | rational<int> pi(22,7); |
92 | cout << "pi = " << boost::rational_cast<double>(src: pi) << " (nearly)" << endl; |
93 | |
94 | // Exception handling |
95 | try { |
96 | rational<int> r; // Forgot to initialise - set to 0 |
97 | r = 1/r; // Boom! |
98 | } |
99 | catch (const boost::bad_rational &e) { |
100 | cout << "Bad rational, as expected: " << e.what() << endl; |
101 | } |
102 | catch (...) { |
103 | cout << "Wrong exception raised!" << endl; |
104 | } |
105 | |
106 | return 0; |
107 | } |
108 | |
109 | |