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