PVS-Studio warning V801 for InstantVNC

typedef struct tagRECT
{
    LONG    left;
    LONG    top;
    LONG    right;
    LONG    bottom;
} RECT, *PRECT, NEAR *NPRECT, FAR *LPRECT;

bool
operator <(const RECT _X, const RECT _Y)
{
  return _X.top < _Y.top;
}

bool
operator >(const RECT _X, const RECT _Y)
{
  return _X.top > _Y.top;
}

This suspicious code was found in InstantVNC project by PVS-Studio static code analyzer.
Warning message is:
V801 Decreased performance. It is better to redefine the first function argument as a reference. Consider replacing 'const .. _X' with 'const .. &_X'. miniWinVNC rectlist.cpp 32

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