std::basic_istringstream::basic_istringstream

(1) empty constructor (default constructor)

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) copy constructor (deleted)

Deleted (no copy constructor).

(4) move constructor

Acquires the contents of x.
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 is left in an unspecified but valid state.
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.

Parameters

str

A basic_string object with the same template parameters (charT, traits and Alloc), whose content is copied.

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:

member constant	stands for	access
ios_base::in*	input	The sequence supports input operations.
ios_base::out	output	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.

member constant	stands for	access
ios_base::in*	input	The sequence supports input operations.
ios_base::out	output	The sequence supports output operations.
ios_base::ate	at end	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.

Example

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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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Data races

Exception safety

See also

basic_istringstream::str

Get/set content (public member function)