create

FormatString.cpp

@@ -0,0 +1,59 @@
+#include "FormatString.h"
+#include <time.h>
+#include <iomanip>
+
+void _formatTime(std::ostringstream &ss, time_t t)
+{
+	struct tm tm1;
+	char szTime[24];
+#ifdef _WIN32
+	localtime_s(&tm1, &t);
+	sprintf_s(szTime, 24, "%04d-%02d-%02d %02d:%02d:%02d",
+		tm1.tm_year + 1900, tm1.tm_mon + 1, tm1.tm_mday,
+		tm1.tm_hour, tm1.tm_min, tm1.tm_sec);
+#else
+	localtime_r(&t, &tm1);
+	snprintf(szTime, 24, "%04d-%02d-%02d %02d:%02d:%02d",
+		tm1.tm_year + 1900, tm1.tm_mon + 1, tm1.tm_mday,
+		tm1.tm_hour, tm1.tm_min, tm1.tm_sec);
+#endif
+
+	ss << szTime;
+}
+
+void _formatItem(std::ostringstream &ss, const std::string& item, const CArgArray& args)
+{
+	//{ index[,alignment][ :formatString] }
+	int index = 0;
+	int alignment = 0;
+	std::string fmt;
+
+	char* endptr = NULL;
+	index = strtol(&item[0], &endptr, 10);
+	if (index < 0 || index >= args.size())
+	{
+		return;
+	}
+
+	if (*endptr == ',')
+	{
+		alignment = strtol(endptr + 1, &endptr, 10);
+		if (alignment > 0)
+		{
+			ss << std::right << std::setw(alignment);
+		}
+		else if (alignment < 0)
+		{
+			ss << std::left << std::setw(-alignment);
+		}
+	}
+	if (*endptr == ':')
+	{
+		fmt = endptr + 1;
+	}
+
+	args[index]->format(ss, fmt);
+	return;
+}
+
+

FormatString.h

@@ -0,0 +1,125 @@
+#ifndef _CS_FORMAT_H
+#define _CS_FORMAT_H
+
+#include <string>
+#include <vector>
+#include <stdlib.h>
+#include <iostream>
+#include <algorithm>
+#include <sstream>
+
+class CArgArray;
+void _formatItem(std::ostringstream &ss, const std::string& item, const CArgArray& args);
+void _formatTime(std::ostringstream &ss, time_t t);
+
+class CArgBase
+{
+public:
+	CArgBase() {}
+	virtual ~CArgBase() {}
+	virtual void format(std::ostringstream &ss, const std::string& fmt) = 0;
+};
+
+template <class T>
+class CArg : public CArgBase
+{
+public:
+	CArg(T arg) :_arg(arg) {}
+	virtual ~CArg(){}
+	virtual void format(std::ostringstream &ss, const std::string& fmt)
+	{
+		ss << _arg;
+	}
+private:
+	T _arg;
+};
+
+//a example of extension
+template <>
+class CArg<time_t> : public CArgBase
+{
+public:
+	CArg(time_t arg) : _arg(arg) {}
+	virtual void format(std::ostringstream &ss, const std::string& fmt)
+	{
+		if (fmt[0] == 'T')
+		{
+			_formatTime(ss, _arg);
+		}
+		else
+		{
+			ss << _arg;
+		}
+	}
+private:
+	time_t _arg;
+};
+
+class CArgArray : public std::vector<CArgBase*>
+{
+public:
+	CArgArray() {}
+	~CArgArray()
+	{
+		std::for_each(begin(), end(), [](CArgBase* p){delete p; });
+	}
+};
+
+template <class T>
+static void transfer(CArgArray& argArray, T t)
+{
+	CArgBase* arg = new CArg<T>(t);
+	argArray.push_back(arg);
+}
+
+template <class T, typename... Args>
+static void transfer(CArgArray& argArray, T t, Args... args)
+{
+	transfer(argArray, t);
+	transfer(argArray, args...);
+}
+
+template <typename... Args>
+std::string CSFormat(const std::string& format, Args... args)
+{
+	if (sizeof...(args) == 0)
+	{
+		return format;
+	}
+
+	CArgArray argArray;
+	transfer(argArray, args...);
+	size_t start = 0;
+	size_t pos = 0;
+	std::ostringstream ss;
+	while (true)
+	{
+		pos = format.find('{', start);
+		ss << format.substr(start, pos - start);
+		if (pos == std::string::npos)
+		{	
+			break;
+		}
+		if (format[pos + 1] == '{')
+		{
+			ss << '{';
+			start = pos + 2;
+			continue;
+		}
+		start = pos + 1;
+		pos = format.find('}', start);
+		if (pos == std::string::npos)
+		{
+			ss << format.substr(start-1);
+			break;
+		}
+
+		_formatItem(ss, format.substr(start, pos - start), argArray);
+
+		start = pos + 1;
+	}
+
+	return ss.str();
+}
+
+#endif

LICENSE.md

@@ -1,3 +1,6 @@
+CSFormat is available for use under the following license
+
+==============================
 The MIT License (MIT)
 
 Copyright (c) 2014 merlin fang

README.md

@@ -16,6 +16,7 @@ Usage
 	#include "FormatString.h"
 	#include <string>
 	#include <iostream>
+	#include <time.h>
 	using namespace std;
 	int main()
 	{

demo.cpp

@@ -0,0 +1,11 @@
+#include "FormatString.h"
+#include <string>
+#include <iostream>
+#include <time.h>
+using namespace std;
+int main()
+{
+	string demo = CSFormat("{0,20}|{1,-10}|{2}|{3,30:T}|", 11, "aaa", 3.14, time(NULL));
+	cout << demo << endl;
+	return 0;
+}