#ifndef ZIG_ZAG_INL_H_ #error "Direct inclusion of this file is not allowed, include zig_zag.h" // For the sake of sane code completion. #include "zig_zag.h" #endif #undef ZIG_ZAG_INL_H_ namespace NYT { //////////////////////////////////////////////////////////////////////////////// inline ui32 ZigZagEncode32(i32 n) { // Note: the right-shift must be arithmetic. // Note: left shift must be unsigned because of overflow. return (static_cast(n) << 1) ^ static_cast(n >> 31); } inline i32 ZigZagDecode32(ui32 n) { // Note: using unsigned types prevent undefined behavior. return static_cast((n >> 1) ^ (~(n & 1) + 1)); } inline ui64 ZigZagEncode64(i64 n) { // Note: the right-shift must be arithmetic. // Note: left shift must be unsigned because of overflow. return (static_cast(n) << 1) ^ static_cast(n >> 63); } inline i64 ZigZagDecode64(ui64 n) { // Note: using unsigned types prevent undefined behavior. return static_cast((n >> 1) ^ (~(n & 1) + 1)); } //////////////////////////////////////////////////////////////////////////////// } // namespace NYT