void emplace(WordId id, std::wstring word){
		auto wp = std::make_shared<std::wstring>(word);
		id_word_.push_back(wp);
		word_id_.emplace(wp, id);
	}
	void emplace(WordId id, C_WStrPtr word){
		id_word_.push_back(word);
		word_id_.emplace(word, id);
	}