strstreambuf::freeze

Causes a stream buffer to be unavailable through stream buffer operations.

void freeze( 
   bool _Freezeit = true 
);

Parameters

• _Freezeit
  A bool indicating whether you want the stream to be frozen.

Remarks

If _Freezeit is true, the function alters the stored strstreambuf mode to make the controlled sequence frozen. Otherwise, it makes the controlled sequence not frozen.

str implies freeze.

Note

A frozen buffer will not be freed during strstreambuf destruction. You must unfreeze the buffer before it is freed to avoid a memory leak.

Example

// strstreambuf_freeze.cpp
// compile with: /EHsc

#include <iostream>
#include <strstream>

using namespace std;

void report(strstream &x)
{
    if (!x.good())
        cout << "stream bad" << endl;
    else
        cout << "stream good" << endl;
}

int main()
{
    strstream x;

    x << "test1";
    cout << "before freeze: ";
    report(x);

    // Calling str freezes stream.
    cout.write(x.rdbuf()->str(), 5) << endl;
    cout << "after freeze: ";
    report(x);

    // Stream is bad now, wrote on frozen stream
    x << "test1.5";
    cout << "after write to frozen stream: ";
    report(x);

    // Unfreeze stream, but it is still bad
    x.rdbuf()->freeze(false);
    cout << "after unfreezing stream: ";
    report(x);

    // Clear stream
    x.clear();
    cout << "after clearing stream: ";
    report(x);

    x << "test3";
    cout.write(x.rdbuf()->str(), 10) << endl;

    // Clean up.  Failure to unfreeze stream will cause a
    // memory leak.
    x.rdbuf()->freeze(false);
}

before freeze: stream good
test1
after freeze: stream good
after write to frozen stream: stream bad
after unfreezing stream: stream bad
after clearing stream: stream good
test1test3

Requirements

Header: <strstream>

Namespace: std

See Also

Reference

strstreambuf Class

iostream Programming

iostreams Conventions