请教C++primer上的问题
C++ primer P234
typedef pair<short,short>location;
typedef vector<location> loc;
typedefvector<string> text;
typedef pair<text*,loc*>text_loc;
text_loc* separate_words(const vector<string> *text_file);
{vector <string> *words=new vector <string>;
vector <locations> *locations=new vector<location>;
short line_pos=0;
for(;line_pos<text_file.size();++line_pos)
{ short word_pos=0;
string textline=(text_file *)[line_pos];
string::size_type pos =0,prev_pos=0;
whlie((pos=textline.find_first_of(' ',pos)!=string::npos)
{ words->push_back(textline.substr(prev_pos,pos-prev_pos));
locations->push_back(make_pair(line_pos,word_pos));
//make_pair()函数是做什么用的?
++word_pos;prev_pos=++pos;
}
words->push_back(textline.substr(prev_pos,pos-prev_pos));
locations->push_back(make_pair(line_pos,word_pos));
}
return new text_loc(words,locations);
}