| 1 | // explore_limits.cpp ----------------------------------------------------------// |
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| 2 | |
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| 3 | // Copyright 2008 Howard Hinnant |
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| 4 | // Copyright 2008 Beman Dawes |
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| 5 | // Copyright 2009 Vicente J. Botet Escriba |
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| 6 | |
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| 7 | // Distributed under the Boost Software License, Version 1.0. |
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| 8 | // See http://www.boost.org/LICENSE_1_0.txt |
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| 9 | |
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| 10 | /* |
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| 11 | This code was extracted by Vicente J. Botet Escriba from Beman Dawes time2_demo.cpp which |
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| 12 | was derived by Beman Dawes from Howard Hinnant's time2_demo prototype. |
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| 13 | Many thanks to Howard for making his code available under the Boost license. |
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| 14 | The original code was modified to conform to Boost conventions and to section |
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| 15 | 20.9 Time utilities [time] of the C++ committee's working paper N2798. |
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| 16 | See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf. |
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| 17 | |
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| 18 | time2_demo contained this comment: |
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| 19 | |
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| 20 | Much thanks to Andrei Alexandrescu, |
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| 21 | Walter Brown, |
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| 22 | Peter Dimov, |
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| 23 | Jeff Garland, |
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| 24 | Terry Golubiewski, |
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| 25 | Daniel Krugler, |
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| 26 | Anthony Williams. |
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| 27 | */ |
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| 28 | |
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| 29 | #include <boost/chrono/chrono.hpp> |
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| 30 | #include <boost/type_traits.hpp> |
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| 31 | |
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| 32 | #include <iostream> |
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| 33 | |
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| 34 | using namespace boost::chrono; |
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| 35 | |
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| 36 | |
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| 37 | void explore_limits() |
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| 38 | { |
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| 39 | typedef duration<long long, boost::ratio_multiply<boost::ratio<24*3652425,10000>, |
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| 40 | hours::period>::type> Years; |
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| 41 | #ifdef BOOST_CHRONO_HAS_CLOCK_STEADY |
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| 42 | steady_clock::time_point t1( Years(250)); |
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| 43 | steady_clock::time_point t2(-Years(250)); |
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| 44 | #else |
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| 45 | system_clock::time_point t1( Years(250)); |
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| 46 | system_clock::time_point t2(-Years(250)); |
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| 47 | #endif |
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| 48 | // nanosecond resolution is likely to overflow. "up cast" to microseconds. |
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| 49 | // The "up cast" trades precision for range. |
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| 50 | microseconds d = time_point_cast<microseconds>(t: t1) - time_point_cast<microseconds>(t: t2); |
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| 51 | std::cout << d.count() << " microseconds\n" ; |
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| 52 | } |
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| 53 | |
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| 54 | |
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| 55 | int main() |
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| 56 | { |
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| 57 | explore_limits(); |
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| 58 | return 0; |
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| 59 | } |
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| 60 | |
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| 61 | |
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