/Src/Dependencies/Boost/boost/graph/numeric_values.hpp
http://hadesmem.googlecode.com/ · C++ Header · 52 lines · 26 code · 10 blank · 16 comment · 0 complexity · 0a6f72c8e2d67c21a0e903a79a219598 MD5 · raw file
- // (C) Copyright 2007-2009 Andrew Sutton
- //
- // Use, modification and distribution are subject to the
- // Boost Software License, Version 1.0 (See accompanying file
- // LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
- #ifndef BOOST_GRAPH_NUMERIC_VALUES_HPP
- #define BOOST_GRAPH_NUMERIC_VALUES_HPP
- #include <limits>
- namespace boost
- {
- #define BOOST_GRAPH_SPECIALIZE_NUMERIC_FLOAT(type) \
- template <> struct numeric_values<type> { \
- typedef type value_type; \
- static type zero() { return 0.0; } \
- static type infinity() { return std::numeric_limits<type>::infinity(); } \
- };
- /**
- * This generic type reports various numeric values for some type. In the
- * general case, numeric values simply treat their maximum value as infinity
- * and the default-constructed value as 0.
- *
- * Specializations of this template can redefine the notions of zero and
- * infinity for various types. For example, the class is specialized for
- * floating point types to use the built in notion of infinity.
- */
- template <typename T>
- struct numeric_values
- {
- typedef T value_type;
- static T zero()
- { return T(); }
- static T infinity()
- { return (std::numeric_limits<T>::max)(); }
- };
- // Specializations for floating point types refer to 0.0 and their infinity
- // value defined by numeric_limits.
- BOOST_GRAPH_SPECIALIZE_NUMERIC_FLOAT(float)
- BOOST_GRAPH_SPECIALIZE_NUMERIC_FLOAT(double)
- BOOST_GRAPH_SPECIALIZE_NUMERIC_FLOAT(long double)
- #undef BOOST_GRAPH_SPECIALIZE_NUMERIC_VALUE
- }
- #endif