std::istrstream:: istrstream

From cppreference.com
C++
Input/output library
std::istrstream
explicit istrstream ( const char * s ) ;
(1) (deprecated in C++98)
(removed in C++26)
explicit istrstream ( char * s ) ;
(2) (deprecated in C++98)
(removed in C++26)
istrstream ( const char * s, std:: streamsize n ) ;
(3) (deprecated in C++98)
(removed in C++26)
istrstream ( char * s, std:: streamsize n ) ;
(4) (deprecated in C++98)
(removed in C++26)

Constructs new std::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

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