split.cpp

来自「Accelerated c++ 電子書 對 c++ container 多有描述」· C++ 代码 · 共 44 行

#include <cctype>
#include <string>
#include <vector>

#include "split.h"

using std::vector;
using std::string;

#ifndef _MSC_VER
using std::isspace;
#endif

vector<string> split(const string& s)
{
	vector<string> ret;
	typedef string::size_type string_size;
	string_size i = 0;

	// invariant: we have processed characters `['original value of `i', `i)'
	while (i != s.size()) {
		// ignore leading blanks
		// invariant: characters in range `['original `i', current `i)' are all spaces
		while (i != s.size() && isspace(s[i]))
			++i;

		// find end of next word
		string_size j = i;
		// invariant: none of the characters in range `['original `j', current `j)' is a space
		while (j != s.size() && !isspace(s[j]))
			++j;

		// if we found some nonwhitespace characters
		if (i != j) {
			// copy from `s' starting at `i' and taking `j' `\-' `i' chars
			ret.push_back(s.substr(i, j - i));
			i = j;
		}

	}
	return ret;
}