ostringstream的使用

大家好，又见面了，我是你们的朋友全栈君。

在std中还有个ostringstream这么方便的格式化输出的工具
 

std::string generate()
{
    ostringstream osm;
    osm << "xxxx " << 1111;
    
    // 清空之前的内容
    osm.str("");
    
    // 浮点数转换限制
    double tmp = 123.1234554351236234;
    osm.precision(15);
    osm.setf(std::ios::fixed); // 将浮点数的位数限定为小数点之后的位数
    osm << tmp; 

    return osm.str();
}

需要包含的头文件：

#include <sstream> 

ostringstream作用、主要接口：

Output string stream class

ios_base  ios  ostream  ostringstream 

ostringstream provides an interface to manipulate strings as if they were output streams.

The objects of this class maintain internally a pointer to a stringbuf object that can be obtained/modified by calling member rdbuf. This streambuf-derived object controls a sequence of characters (string) that can be obtained/modified by calling member str.


Public members
(constructor) Construct an object and optionally initialize its content (constructor member) 
rdbuf Get/set the associated stringbuf object (public member function) 
str Get/set the associated string object (public member function) 

一个非常简单又快捷的格式化输出工具。