boost/ratio/ratio.hpp

0001 //  ratio.hpp  ---------------------------------------------------------------//
0002
0003 //  Copyright 2008 Howard Hinnant
0004 //  Copyright 2008 Beman Dawes
0005 //  Copyright 2009 Vicente J. Botet Escriba
0006
0007 //  Distributed under the Boost Software License, Version 1.0.
0008 //  See http://www.boost.org/LICENSE_1_0.txt
0009
0010 /*
0011
0012 This code was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
0013 Many thanks to Howard for making his code available under the Boost license.
0014 The original code was modified to conform to Boost conventions and to section
0015 20.4 Compile-time rational arithmetic [ratio], of the C++ committee working
0016 paper N2798.
0017 See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
0018
0019 time2_demo contained this comment:
0020
0021     Much thanks to Andrei Alexandrescu,
0022                    Walter Brown,
0023                    Peter Dimov,
0024                    Jeff Garland,
0025                    Terry Golubiewski,
0026                    Daniel Krugler,
0027                    Anthony Williams.
0028 */
0029
0030 // The way overflow is managed for ratio_less is taken from llvm/libcxx/include/ratio
0031
0032 #ifndef BOOST_RATIO_RATIO_HPP
0033 #define BOOST_RATIO_RATIO_HPP
0034
0035 #include <boost/ratio/ratio_fwd.hpp>
0036 #include <boost/ratio/detail/gcd_lcm.hpp>
0037
0038 namespace boost
0039 {
0040
0041 // extension used by Chrono
0042
0043 template <class R1, class R2> using ratio_gcd = typename ratio<
0044     ratio_detail::gcd<R1::num, R2::num>::value,
0045     ratio_detail::lcm<R1::den, R2::den>::value>::type;
0046
0047 }  // namespace boost
0048
0049 #endif  // BOOST_RATIO_RATIO_HPP