library/cpp/yson_pull/detail/zigzag.h


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#pragma once 
 
#include "traits.h" 
 
namespace NYsonPull {
    namespace NDetail {
        namespace NZigZag {
            //! Functions that provide coding of integers with property: 0 <= f(x) <= 2 * |x|
 
            template <typename TSigned> 
            inline NTraits::to_unsigned<TSigned> encode(TSigned x) { 
                using TUnsigned = NTraits::to_unsigned<TSigned>; 
                constexpr auto rshift = sizeof(TSigned) * 8 - 1; 
                return (static_cast<TUnsigned>(x) << 1) ^ static_cast<TUnsigned>(x >> rshift); 
            }
 
            template <typename TUnsigned> 
            inline NTraits::to_signed<TUnsigned> decode(TUnsigned x) { 
                using TSigned = NTraits::to_signed<TUnsigned>; 
                return static_cast<TSigned>(x >> 1) ^ -static_cast<TSigned>(x & 1); 
            }
        }
    }     // namespace NDetail
}