std::basic_istringstream::basic_istringstream

(1) 空构造函数 (默认构造函数)

Constructs a basic_istringstream object with an empty sequence as content.
Internally, its basic_istream base constructor is passed a pointer to a basic_stringbuf object constructed with an argument based on which.

(2) initialization constructor

Constructs a basic_istringstream object with a copy of str as content.
Internally, its basic_istream base constructor is passed a pointer to a basic_stringbuf object constructed with arguments based on str and which.

(3) 复制构造函数 (已删除)

已删除 (无复制构造函数)。

(4) move constructor

获取 x 的内容。
First, the function move-constructs both its base basic_istream class from x and a basic_stringbuf object from x's internal basic_streambuf object, and then associates them by calling member set_rdbuf.
x 处于未指定但有效的状态。
It is unspecified whether the sequence controlled by the internal basic_stringbuf object is the one in x before the call, or a copy of it. In any case, both objects have internal string buffers that use independent sequences after the call.

参数

str

一个具有相同模板参数（charT、traits和Alloc）的basic_string对象，其内容被复制。

x

A basic_istringstream object of the same type (with the same class template parameters charT, traits and Alloc), whose value is moved.

which

Open mode: Access given by the internal basic_stringbuf object to its internal sequence of characters. It is an object of member type openmode for which any combination of the following member values is significant

成员常量	代表	access
ios_base::in*	输入	The sequence supports input operations.
ios_base::out	输出	The sequence supports output operations.

Other values of type ios_base::openmode may also be specified, although whether they have an effect on basic_istringstream objects depends on the library implementation.

成员常量	代表	access
ios_base::in*	输入	The sequence supports input operations.
ios_base::out	输出	The sequence supports output operations.
ios_base::ate	在末尾	The writing position is at the end after construction, and after every time the content is reset with member str.

Other values of type ios_base::openmode (such as ios_base::app) may also be specified, although whether they have an effect on basic_istringstream objects depends on the library implementation.

* ios_base::in is always set for basic_istringstream objects (even if explicitly not set in argument which).
Note that even though basic_istringstream is an input stream, its internal basic_stringbuf object may be set to also support output operations. This influences certain operations, such as putback, that in basic_istringstream may alter the contents of the sequence.

示例

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// istringstream constructors.
#include <iostream>     // std::cout
#include <sstream>      // std::istringstream
#include <string>       // std::string

int main () {

  std::string stringvalues = "125 320 512 750 333";
  std::istringstream iss (stringvalues);

  for (int n=0; n<5; n++)
  {
    int val;
    iss >> val;
    std::cout << val*2 << '\n';
  }

  return 0;
}

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数据竞争

异常安全

另见

basic_istringstream::str

获取/设置内容 (公共成员函数)