C++ String常用操作接口封装

 
#ifndef __STRING_H__
#define __STRING_H__

#include <algorithm>
#include <cctype>
#include <iostream>
#include <iterator>
#include <limits>
#include <sstream>
#include <string>
#include <vector>

namespace String {

template<int (&F)(int)>
int TypeCheck(unsigned char c) {
	return F(c);
}

inline bool EndsWith(const std::string &s, char ch) {
	return !s.empty() && s.back() == ch;
}

inline bool EndsWith(const std::string &s, const std::string &suffix) {
	return std::mismatch(suffix.rbegin(), suffix.rend(), s.rbegin()).first == suffix.rend();
}

inline bool StartsWith(const std::string &s, char ch) {
	return !s.empty() && s.front() == ch;
}

inline bool StartsWith(const std::string &s, const std::string &prefix) {
	return std::mismatch(prefix.begin(), prefix.end(), s.begin()).first == prefix.end();
}

inline void RTrim(std::string &s) {
	s.erase(std::find_if(s.rbegin(), s.rend(), [](int ch) {
		 return !TypeCheck<std::isspace>(ch);
	 }).base(), s.end());
}

inline void LTrim(std::string &s) {
	s.erase(s.begin(), std::find_if(s.begin(), s.end(), [](int ch) {
		return !TypeCheck<std::isspace>(ch);
	}));
}

inline void Trim(std::string &s) {
	LTrim(s);
	RTrim(s);
}

inline std::string RTrimCopy(std::string s) {
	RTrim(s);
	return s;
}

inline std::string LTrimCopy(std::string s) {
	LTrim(s);
	return s;
}

inline std::string TrimCopy(std::string &s) {
	Trim(s);
	return s;
}

inline void ToUpper(std::string &s) {
	std::transform(s.begin(), s.end(), s.begin(), [](int ch) {
		return std::toupper(ch);
	});
}

inline void ToLower(std::string &s) {
	std::transform(s.begin(), s.end(), s.begin(), [](int ch) {
		return std::tolower(ch);
	});
}

inline std::string ToupperCopy(std::string s) {
	ToUpper(s);
	return s;
}

inline std::string TolowerCopy(std::string s) {
	ToLower(s);
	return s;
}

//------------------------------------------------------------------------------
// Desc: join elements with a char
//------------------------------------------------------------------------------
inline std::string Implode(char glue, const std::vector<std::string> &pieces) {
	std::string s;
	if(!pieces.empty()) {
		s.append(pieces[0]);
		for(size_t i = 1; i < pieces.size(); ++i) {
			s.push_back(glue);
			s.append(pieces[i]);
		}
	}
	return s;
}

//------------------------------------------------------------------------------
// Desc: join elements with a string
//------------------------------------------------------------------------------
inline std::string Implode(const std::string &glue, const std::vector<std::string> &pieces) {
	std::string s;
	if(!pieces.empty()) {
		s.append(pieces[0]);
		for(size_t i = 1; i < pieces.size(); ++i) {
			s.append(glue);
			s.append(pieces[i]);
		}
	}
	return s;
}

inline std::vector<std::string> Explode(const std::string &delimeter, const std::string &string, int limit) {
	std::vector<std::string> r;

	if(!string.empty()) {
		if(limit >= 0) {
			if(limit == 0) {
				limit = 1;
			}

			size_t first = 0;
			size_t last  = string.find(delimeter);

			while(last != std::string::npos) {

				if(--limit == 0) {
					break;
				}

				r.emplace_back(string.substr(first, last - first));
				first = last + delimeter.size();
				last  = string.find(delimeter, last + delimeter.size());
			}

			r.emplace_back(string.substr(first));
		} else {
			size_t first = 0;
			size_t last  = string.find(delimeter);

			while(last != std::string::npos) {
				r.emplace_back(string.substr(first, last - first));
				first = last + delimeter.size();
				last  = string.find(delimeter, last + delimeter.size());
			}

			r.emplace_back(string.substr(first));
			
			while(limit < 0) {
				r.pop_back();
				++limit;
			}
		}
	}
	
	return r;
}

inline std::vector<std::string> Explode(const std::string &delimeter, const std::string &string) {
	return Explode(delimeter, string, std::numeric_limits<int>::max());
}

inline std::vector<std::string> Explode(char delimeter, const std::string &string, int limit) {
	std::vector<std::string> r;

	if(!string.empty()) {
		if(limit >= 0) {
			if(limit == 0) {
				limit = 1;
			}

			size_t first = 0;
			size_t last  = string.find(delimeter);

			while(last != std::string::npos) {

				if(--limit == 0) {
					break;
				}

				r.emplace_back(string.substr(first, last - first));
				first = last + 1;
				last  = string.find(delimeter, last + 1);
			}

			r.emplace_back(string.substr(first));
		} else {
			size_t first = 0;
			size_t last  = string.find(delimeter);

			while(last != std::string::npos) {
				r.emplace_back(string.substr(first, last - first));
				first = last + 1;
				last  = string.find(delimeter, last + 1);
			}

			r.emplace_back(string.substr(first));
			
			while(limit < 0) {
				r.pop_back();
				++limit;
			}
		}
	}
	
	return r;
}

inline std::vector<std::string> Explode(char delimeter, const std::string &string) {
	return Explode(delimeter, string, std::numeric_limits<int>::max());
}

template <class Op>
void Split(const std::string &s, char delim, Op op) {
	std::stringstream ss(s);
	for(std::string item; std::getline(ss, item, delim); ) {
		*op++ = item;
	}
}

inline std::vector<std::string> Split(const std::string &s, char delim) {
    std::vector<std::string> elems;
    Split(s, delim, std::back_inserter(elems));
    return elems;
}

}

#endif