std::istrstream::istrstream

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Input/output library

I/O manipulators

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

strstreambuf (deprecated in C++98)

basic_syncbuf (C++20)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

istrstream (deprecated in C++98)

ostrstream (deprecated in C++98)

strstream (deprecated in C++98)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

std::istrstream

Member functions

istrstream::istrstream

istrstream::~istrstream

istrstream::rdbuf

istrstream::str

 

explicit istrstream(const char* s);	(1)
explicit istrstream(char* s);	(2)
istrstream(const char* s, std::streamsize n);	(3)
istrstream(char* s, std::streamsize n);	(4)

Constructs new istrstream and its underlying std::strstreambuf.

1,2) Constructs the underlying std::strstreambuf by calling strstreambuf(s,0) and initializes the base class with the address of the strstreambuf. The behavior is undefined if s is not pointing at an element of a null-terminated array.

3,4) Constructs the underlying std::strstreambuf by calling strstreambuf(s,n) and initializes the base class with the address of the strstreambuf. The behavior is undefined if s is not pointing at an element of an array whose length is at least n elements.

Parameters

s	-	C-string or char array to use as the contents of the stream
n	-	size of the array

Example

Run this code

#include <iostream>
#include <strstream>
 
int main()
{
    std::istrstream s1("1 2 3"); // string literal
    int n1,n2,n3;
    if(s1 >> n1 >> n2 >> n3)
        std::cout << n1 << ", " << n2 << ", " << n3 << '\n';
 
    char arr[] = {'4', ' ', '5', ' ', '6'};
    std::istrstream s2(arr, sizeof arr);
    if(s2 >> n1 >> n2 >> n3)
        std::cout << n1 << ", " << n2 << ", " << n3 << '\n';
}

Output:

1, 2, 3
4, 5, 6

See also

(constructor)	constructs a strstreambuf object (public member function of std::strstreambuf)
(constructor)	constructs an strstream, optionally allocating the buffer (public member function of std::ostrstream)
(constructor)	constructs an strstream, optionally allocating the buffer (public member function of std::strstream)