std::basic_istringstream<CharT,Traits,Allocator>::str

Since C++20

Manages the contents of the underlying string object.

# Declarations

std::basic_string<CharT, Traits, Allocator> str() const;

(until C++20)

std::basic_string<CharT, Traits, Allocator> str() const&;

(since C++20)

template< class SAlloc >
std::basic_string<CharT, Traits, SAlloc> str( const SAlloc& a ) const;

(since C++20)

std::basic_string<CharT, Traits, Allocator> str() &&;

(since C++20)

void str( const std::basic_string<CharT, Traits, Allocator>& s );

template< class SAlloc >
void str( const std::basic_string<CharT, Traits, SAlloc>& s );

(since C++20)

void str( std::basic_string<CharT, Traits, Allocator>&& s );

(since C++20)

template< class StringViewLike >
void str( const StringViewLike& t );

(since C++26)

# Parameters

# Notes

The copy of the underlying string returned by str is a temporary object that will be destructed at the end of the expression, so directly calling c_str() on the result of str() (for example in auto *ptr = out.str().c_str();) results in a dangling pointer.

# Example

#include <iostream>
#include <sstream>
 
int main()
{
    int n;
 
    std::istringstream in; // could also use in("1 2")
    in.str("1 2");
    in >> n;
    std::cout << "After reading the first int from \"1 2\", the int is "
              << n << ", str() = \"" << in.str() << "\"\n";
 
    std::ostringstream out("1 2");
    out << 3;
    std::cout << "After writing the int '3' to output stream \"1 2\""
              << ", str() = \"" << out.str() << "\"\n";
 
    std::ostringstream ate("1 2", std::ios_base::ate);
    ate << 3;
    std::cout << "After writing the int '3' to append stream \"1 2\""
              << ", str() = \"" << ate.str() << "\"\n";
}

# See also