C/C++ 实现printf函数

include <iostream>
#include <iomanip>
#include <stdarg.h>

void stl_printf(const char* s)
{
	while (*s)
	{
		std::cout << *s++;
	}
}

template<typename TValue, typename...TArgs>
void stl_printf(const char* s, TValue value, TArgs... args)
{
	while (*s)
	{
		if (*s == '%' && (*++s) != '%')
		{
			std::cout<<value;
			stl_printf(*s ? ++s : s, args...);
			return;
		}

		std::cout<<*s++;
	}
}


void c_printf(char c, va_list& args)
{
	switch (c)
	{
	case 'd':
		std::cout << va_arg(args, int);
		break;
	case 'c':
		std::cout << va_arg(args, char);
		break;
	case 'f':
		std::cout<<std::fixed<< va_arg(args, double);
		break;
	case 's':
		std::cout << va_arg(args, char*);
		break;
	}
}

void c_printf(const char* s, ...)
{

	va_list args;
	va_start(args, s);

	while (*s)
	{
		if (*s == '%' && *(++s) != '%')
		{
			c_printf(*s++, args);
		}
		else
		{
			std::cout << *s++;
		}
	}

	va_end(args);

}


int main(int argc, char* argv[])
{
    stl_printf("hello %s_%d_%f", "vison0300", 123, 0.123);
	c_printf("hello %s_%d_%f", "vison0300", 123, 0.123);

	char c;
	std::cin >> c;
	return 0;
}

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转载自blog.csdn.net/vison0300/article/details/82192260