          else:
              xp = get_array_module(self.data)
              self.data = xp.resize(self.data, shape)
          filled = {row for row in self.key2row.values()}
          self._unset = {row for row in range(shape[0]) if row not in filled}
          removed_items = []
          for key, row in list(self.key2row.items()):
              if row >= shape[0]:
                  self.key2row.pop(key)
                  removed_items.append((key, row))
 
</s> remove             self._unset = set(range(self.data.shape[0]))
 </s> add             self._unset = cppset[int]({i for i in range(self.data.shape[0])}) </s> remove             self._unset = set()
 </s> add             self._unset = cppset[int]() </s> remove                 if row in self._unset:
                    self._unset.remove(row)
 </s> add                 if self._unset.count(row):
                    self._unset.erase(self._unset.find(row)) </s> remove             row = min(self._unset)
 </s> add             row = deref(self._unset.begin()) </s> remove             if row in self._unset:
                self._unset.remove(row)
 </s> add             if self._unset.count(row):
                self._unset.erase(self._unset.find(row))
        self._unset = cppset[int]({row for row in range(shape[0]) if row not in filled})
          else:
              xp = get_array_module(self.data)
              self.data = xp.resize(self.data, shape)
          filled = {row for row in self.key2row.values()}
        self._unset = cppset[int]({row for row in range(shape[0]) if row not in filled})
          removed_items = []
          for key, row in list(self.key2row.items()):
              if row >= shape[0]:
                  self.key2row.pop(key)
                  removed_items.append((key, row))
keep keep keep keep replace keep keep keep keep keep
 [2032] - Changed python set to cpp stl set (#2170)

Changed python set to cpp stl set #2032 

## Description

Changed python set to cpp stl set. CPP stl set works better due to the logarithmic run time of its methods. Finding minimum in the cpp set is done in constant time as opposed to the worst case linear runtime of python set. Operations such as find,count,insert,delete are also done in either constant and logarithmic time thus making cpp set a better option to manage vectors.
Reference : http://www.cplusplus.com/reference/set/set/

### Types of change
Enhancement for `Vectors` for faster initialising of word vectors(fasttext) 
spacy/vectors.pyx