Added thirdparty: boost library

thirdparty/include/boost/ratio/ratio_fwd.hpp

@@ -0,0 +1,83 @@
+//  ratio_fwd.hpp  ---------------------------------------------------------------//
+
+//  Copyright 2008 Howard Hinnant
+//  Copyright 2008 Beman Dawes
+//  Copyright 2009 Vicente J. Botet Escriba
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+/*
+
+This code was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
+Many thanks to Howard for making his code available under the Boost license.
+The original code was modified to conform to Boost conventions and to section
+20.4 Compile-time rational arithmetic [ratio], of the C++ committee working
+paper N2798.
+See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
+
+time2_demo contained this comment:
+
+    Much thanks to Andrei Alexandrescu,
+                   Walter Brown,
+                   Peter Dimov,
+                   Jeff Garland,
+                   Terry Golubiewski,
+                   Daniel Krugler,
+                   Anthony Williams.
+*/
+
+// The way overflow is managed for ratio_less is taken from llvm/libcxx/include/ratio
+
+#ifndef BOOST_RATIO_RATIO_FWD_HPP
+#define BOOST_RATIO_RATIO_FWD_HPP
+
+#include <ratio>
+
+namespace boost
+{
+
+//----------------------------------------------------------------------------//
+//                                                                            //
+//              20.6 Compile-time rational arithmetic [ratio]                 //
+//                                                                            //
+//----------------------------------------------------------------------------//
+
+// ratio
+using std::ratio;
+
+// ratio arithmetic
+using std::ratio_add;
+using std::ratio_subtract;
+using std::ratio_multiply;
+using std::ratio_divide;
+
+// ratio comparison
+using std::ratio_equal;
+using std::ratio_not_equal;
+using std::ratio_less;
+using std::ratio_less_equal;
+using std::ratio_greater;
+using std::ratio_greater_equal;
+
+// convenience SI typedefs
+using std::atto;
+using std::femto;
+using std::pico;
+using std::nano;
+using std::micro;
+using std::milli;
+using std::centi;
+using std::deci;
+using std::deca;
+using std::hecto;
+using std::kilo;
+using std::mega;
+using std::giga;
+using std::tera;
+using std::peta;
+using std::exa;
+
+}  // namespace boost
+
+#endif  // BOOST_RATIO_RATIO_FWD_HPP