View Compilation Error

0_0_6554169_3236.cpp: In function `int main()':
0_0_6554169_3236.cpp:77: error: no match for 'operator!' in '!(&hash)->std::map<_Key, _Tp, _Compare, _Alloc>::find [with _Key = point, _Tp = int, _Compare = std::less<point>, _Alloc = std::allocator<std::pair<const point, int> >](((const point&)((const point*)(&p))))'
0_0_6554169_3236.cpp:77: note: candidates are: operator!(bool) <built-in>