Add SCons configure checks

[senf.git] / boost_ext / boost / typeof / int_encoding.hpp

diff --git a/boost_ext/boost/typeof/int_encoding.hpp b/boost_ext/boost/typeof/int_encoding.hpp
new file mode 100644 (file)
index 0000000..552c250
--- /dev/null
+++ b/boost_ext/boost/typeof/int_encoding.hpp
@@ -0,0 +1,116 @@
+// 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 BOOST_TYPEOF_INT_ENCODING_HPP_INCLUDED
+#define BOOST_TYPEOF_INT_ENCODING_HPP_INCLUDED
+
+#include <boost/mpl/if.hpp>
+#include <boost/mpl/size_t.hpp>
+
+namespace boost { 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
+    {
+        enum {value = (n + 1) * 2 + (Overflow ? 1 : 0)};
+    };
+
+    template<std::size_t m> 
+    struct unpack
+    {
+        enum {value = (m / 2) - 1};
+        enum {overflow = (m % 2 == 1)};
+    };
+
+    ////////////////////////////////
+
+    template<class V, std::size_t n, bool overflow = (n >= 0x3fffffff)>
+    struct encode_size_t : push_back<
+        V, 
+        boost::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,
+        boost::mpl::size_t<pack<n % 0x3ffffffe, true>::value> >::type,
+        boost::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>
+    {
+        enum {value = n};
+        typedef Iter iter;
+    };
+
+    template<std::size_t n, class Iter> 
+    struct decode_size_t<n, Iter, true>
+    {
+        enum {m = Iter::type::value};
+
+        enum {value = (std::size_t)m * 0x3ffffffe + n};
+        typedef typename Iter::next iter;
+    };
+
+    template<class T, class Iter>
+    struct decode_integral
+    {
+        enum {m = Iter::type::value};
+
+        enum {n = unpack<m>::value};
+
+        enum {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<n, nextpos, overflow>::iter iter;
+    };
+
+}}//namespace 
+
+#endif//BOOST_TYPEOF_INT_ENCODING_HPP_INCLUDED