去除string中空格的方法

转自出处

http://stackoverflow.com/questions/83439/remove-spaces-from-stdstring-in-c

The best thing to do is to use the algorithm remove_if and isspace:

remove_if(str.begin(), str.end(), isspace);

Now the algorithm itself can't change the container(only modify the values), so it actually shuffles the values around and returns a pointer to where the end now should be. So we have to call string::erase to actually modify the length of the container:

str.erase(remove_if(str.begin(), str.end(), isspace), str.end());

We should also note that remove_if will make at most one copy of the data. Here is a sample implementation:

template<typename T, typename P> T remove_if(T beg, T end, P pred) { T dest = beg; for (T itr = beg;itr != end; ++itr) if (!pred(*itr)) *(dest++) = *itr; return dest; }