| // Copyright (C) 2004 Arkadiy Vertleyb |
| // Use, modification and distribution is subject to the Boost Software |
| // License, Version 1.0. (http://www.boost.org/LICENSE_1_0.txt) |
| |
| #ifndef NDNBOOST_TYPEOF_INT_ENCODING_HPP_INCLUDED |
| #define NDNBOOST_TYPEOF_INT_ENCODING_HPP_INCLUDED |
| |
| #include <ndnboost/mpl/if.hpp> |
| #include <ndnboost/mpl/size_t.hpp> |
| #include <ndnboost/config.hpp> |
| |
| namespace ndnboost { namespace type_of { |
| |
| template<class T> struct get_unsigned |
| { |
| typedef T type; |
| }; |
| template<> struct get_unsigned<signed char> |
| { |
| typedef unsigned char type; |
| }; |
| template<> struct get_unsigned<char> |
| { |
| typedef unsigned char type; |
| }; |
| template<> struct get_unsigned<short> |
| { |
| typedef unsigned short type; |
| }; |
| template<> struct get_unsigned<int> |
| { |
| typedef unsigned int type; |
| }; |
| template<> struct get_unsigned<long> |
| { |
| typedef unsigned long type; |
| }; |
| |
| ////////////////////////// |
| |
| template<std::size_t n, bool Overflow> |
| struct pack |
| { |
| NDNBOOST_STATIC_CONSTANT(std::size_t , value=((n + 1) * 2 + (Overflow ? 1 : 0))); |
| }; |
| |
| template<std::size_t m> |
| struct unpack |
| { |
| NDNBOOST_STATIC_CONSTANT(std::size_t, value = (m / 2) - 1); |
| NDNBOOST_STATIC_CONSTANT(std::size_t, overflow = (m % 2 == 1)); |
| }; |
| |
| //////////////////////////////// |
| |
| template<class V, std::size_t n, bool overflow = (n >= 0x3fffffff)> |
| struct encode_size_t : push_back< |
| V, |
| ndnboost::mpl::size_t<pack<n, false>::value> |
| > |
| {}; |
| |
| template<class V, std::size_t n> |
| struct encode_size_t<V, n, true> : push_back<typename push_back< |
| V, |
| ndnboost::mpl::size_t<pack<n % 0x3ffffffe, true>::value> >::type, |
| ndnboost::mpl::size_t<n / 0x3ffffffe> |
| > |
| {}; |
| |
| template<class V, class T, T n> |
| struct encode_integral : encode_size_t< V, (typename get_unsigned<T>::type)n,(((typename get_unsigned<T>::type)n)>=0x3fffffff) > |
| {}; |
| |
| template<class V, bool b> |
| struct encode_integral<V, bool, b> : encode_size_t< V, b?1:0, false> |
| {}; |
| /////////////////////////// |
| |
| template<std::size_t n, class Iter, bool overflow> |
| struct decode_size_t; |
| |
| template<std::size_t n, class Iter> |
| struct decode_size_t<n, Iter, false> |
| { |
| NDNBOOST_STATIC_CONSTANT(std::size_t,value = n); |
| typedef Iter iter; |
| }; |
| |
| template<std::size_t n, class Iter> |
| struct decode_size_t<n, Iter, true> |
| { |
| NDNBOOST_STATIC_CONSTANT(std::size_t,m = Iter::type::value); |
| |
| NDNBOOST_STATIC_CONSTANT(std::size_t,value = (std::size_t)m * 0x3ffffffe + n); |
| typedef typename Iter::next iter; |
| }; |
| |
| template<class T, class Iter> |
| struct decode_integral |
| { |
| typedef decode_integral<T,Iter> self_t; |
| NDNBOOST_STATIC_CONSTANT(std::size_t,m = Iter::type::value); |
| |
| NDNBOOST_STATIC_CONSTANT(std::size_t,n = unpack<m>::value); |
| |
| NDNBOOST_STATIC_CONSTANT(std::size_t,overflow = unpack<m>::overflow); |
| |
| typedef typename Iter::next nextpos; |
| |
| static const T value = (T)(std::size_t)decode_size_t<n, nextpos, overflow>::value; |
| |
| typedef typename decode_size_t<self_t::n, nextpos, self_t::overflow>::iter iter; |
| }; |
| |
| }}//namespace |
| |
| #endif//NDNBOOST_TYPEOF_INT_ENCODING_HPP_INCLUDED |