std::strstreambuf::~strstreambuf

 

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::strstreambuf

Public member functions

strstreambuf::strstreambuf

strstreambuf::~strstreambuf

strstreambuf::freeze

strstreambuf::str

strstreambuf::pcount

Protected member functions

strstreambuf::underflow

strstreambuf::pbackfail

strstreambuf::overflow

strstreambuf::setbuf

strstreambuf::seekoff

strstreambuf::seekpos

 

virtual ~strstreambuf();

Destroys a std::strstreambuf object. if the object is managing a dynamically-allocated buffer (the buffer state is "allocated") and if the object is not frozen, then deallocates the buffer using the deallocation function provided at construction or delete[] if none was provided.

Parameters

(none)

Notes

This destructor is typically called by the destructor of std::strstream

If str() was called on a dynamic strstream and freeze(false) was not called after that, this destructor leaks memory.

Example

Run this code

#include <strstream>
#include <iostream>
 
void* my_alloc(size_t n)
{
    std::cout << "my_alloc(" << n << ") called\n";
    return new char[n];
}
 
void my_free(void* p)
{
    std::cout << "my_free() called\n";
    delete[] (char*)p;
}
 
int main()
{
    {
        std::strstreambuf buf(my_alloc, my_free);
        std::ostream s(&buf);
        s << 1.23 << std::ends;
        std::cout << buf.str() << '\n';
        buf.freeze(false);
    } // destructor called here, buffer deallocated
 
    {
        std::strstreambuf buf(my_alloc, my_free);
        std::ostream s(&buf);
        s << 1.23 << std::ends;
        std::cout << buf.str() << '\n';
//        buf.freeze(false);
    } // destructor called here, memory leak!
}

Output:

my_alloc(4096) called
1.23
my_free() called
my_alloc(4096) called
1.23