projects / ceph.git / blame
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|---|---|---|
| 7c673cae FG |
1 | /////////////////////////////////////////////////////////////// |
| 2 | // Copyright 2013 John Maddock. Distributed under the Boost | |
| 3 | // Software License, Version 1.0. (See accompanying file | |
| 92f5a8d4 | 4 | // LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt |
| 7c673cae FG |
5 | |
| 6 | //[logged_adaptor | |
| 7 | ||
| 8 | #include <boost/multiprecision/mpfi.hpp> | |
| 9 | #include <boost/multiprecision/logged_adaptor.hpp> | |
| 10 | #include <iostream> | |
| 11 | #include <iomanip> | |
| 12 | // | |
| 13 | // Begin by overloading log_postfix_event so we can capture each arithmetic event as it happens: | |
| 14 | // | |
| 15 | namespace boost{ namespace multiprecision{ | |
| 16 | ||
| 17 | template <unsigned D> | |
| 18 | inline void log_postfix_event(const mpfi_float_backend<D>& val, const char* event_description) | |
| 19 | { | |
| 20 | // Print out the (relative) diameter of the interval: | |
| 21 | using namespace boost::multiprecision; | |
| 22 | number<mpfr_float_backend<D> > diam; | |
| 23 | mpfi_diam(diam.backend().data(), val.data()); | |
| 24 | std::cout << "Diameter was " << diam << " after operation: " << event_description << std::endl; | |
| 25 | } | |
| 26 | template <unsigned D, class T> | |
| 27 | inline void log_postfix_event(const mpfi_float_backend<D>&, const T&, const char* event_description) | |
| 28 | { | |
| 29 | // This version is never called in this example. | |
| 30 | } | |
| 31 | ||
| 32 | }} | |
| 33 | ||
| 34 | ||
| 35 | int main() | |
| 36 | { | |
| 37 | using namespace boost::multiprecision; | |
| 38 | typedef number<logged_adaptor<mpfi_float_backend<17> > > logged_type; | |
| 39 | // | |
| 40 | // Test case deliberately introduces cancellation error, relative size of interval | |
| 41 | // gradually gets larger after each operation: | |
| 42 | // | |
| 43 | logged_type a = 1; | |
| 44 | a /= 10; | |
| 45 | ||
| 46 | for(unsigned i = 0; i < 13; ++i) | |
| 47 | { | |
| 48 | logged_type b = a * 9; | |
| 49 | b /= 10; | |
| 50 | a -= b; | |
| 51 | } | |
| 52 | std::cout << "Final value was: " << a << std::endl; | |
| 53 | return 0; | |
| 54 | } | |
| 55 | ||
| 56 | //] | |
| 57 | ||
| 58 | /* | |
| 59 | //[logged_adaptor_output | |
| 60 | ||
| 61 | Diameter was nan after operation: Default construct | |
| 62 | Diameter was 0 after operation: Assignment from arithmetic type | |
| 63 | Diameter was 4.33681e-18 after operation: /= | |
| 64 | Diameter was nan after operation: Default construct | |
| 65 | Diameter was 7.70988e-18 after operation: * | |
| 66 | Diameter was 9.63735e-18 after operation: /= | |
| 67 | Diameter was 1.30104e-16 after operation: -= | |
| 68 | Diameter was nan after operation: Default construct | |
| 69 | Diameter was 1.30104e-16 after operation: * | |
| 70 | Diameter was 1.38537e-16 after operation: /= | |
| 71 | Diameter was 2.54788e-15 after operation: -= | |
| 72 | Diameter was nan after operation: Default construct | |
| 73 | Diameter was 2.54788e-15 after operation: * | |
| 74 | Diameter was 2.54863e-15 after operation: /= | |
| 75 | Diameter was 4.84164e-14 after operation: -= | |
| 76 | Diameter was nan after operation: Default construct | |
| 77 | Diameter was 4.84164e-14 after operation: * | |
| 78 | Diameter was 4.84221e-14 after operation: /= | |
| 79 | Diameter was 9.19962e-13 after operation: -= | |
| 80 | Diameter was nan after operation: Default construct | |
| 81 | Diameter was 9.19962e-13 after operation: * | |
| 82 | Diameter was 9.19966e-13 after operation: /= | |
| 83 | Diameter was 1.74793e-11 after operation: -= | |
| 84 | Diameter was nan after operation: Default construct | |
| 85 | Diameter was 1.74793e-11 after operation: * | |
| 86 | Diameter was 1.74793e-11 after operation: /= | |
| 87 | Diameter was 3.32107e-10 after operation: -= | |
| 88 | Diameter was nan after operation: Default construct | |
| 89 | Diameter was 3.32107e-10 after operation: * | |
| 90 | Diameter was 3.32107e-10 after operation: /= | |
| 91 | Diameter was 6.31003e-09 after operation: -= | |
| 92 | Diameter was nan after operation: Default construct | |
| 93 | Diameter was 6.31003e-09 after operation: * | |
| 94 | Diameter was 6.31003e-09 after operation: /= | |
| 95 | Diameter was 1.19891e-07 after operation: -= | |
| 96 | Diameter was nan after operation: Default construct | |
| 97 | Diameter was 1.19891e-07 after operation: * | |
| 98 | Diameter was 1.19891e-07 after operation: /= | |
| 99 | Diameter was 2.27792e-06 after operation: -= | |
| 100 | Diameter was nan after operation: Default construct | |
| 101 | Diameter was 2.27792e-06 after operation: * | |
| 102 | Diameter was 2.27792e-06 after operation: /= | |
| 103 | Diameter was 4.32805e-05 after operation: -= | |
| 104 | Diameter was nan after operation: Default construct | |
| 105 | Diameter was 4.32805e-05 after operation: * | |
| 106 | Diameter was 4.32805e-05 after operation: /= | |
| 107 | Diameter was 0.00082233 after operation: -= | |
| 108 | Diameter was nan after operation: Default construct | |
| 109 | Diameter was 0.00082233 after operation: * | |
| 110 | Diameter was 0.00082233 after operation: /= | |
| 111 | Diameter was 0.0156243 after operation: -= | |
| 112 | Diameter was nan after operation: Default construct | |
| 113 | Diameter was 0.0156243 after operation: * | |
| 114 | Diameter was 0.0156243 after operation: /= | |
| 115 | Diameter was 0.296861 after operation: -= | |
| 116 | Final value was: {8.51569e-15,1.14843e-14} | |
| 117 | ||
| 118 | //] | |
| 119 | */ |