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std::strstream::freeze

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< cpp‎ | io‎ | strstream
Revision as of 13:25, 9 December 2012 by Cubbi (Talk | contribs)

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void freeze(bool flag = true);

If the stream is using a dynamically-allocated array for output, disables (flag == true) or enables (flag == false) automatic allocation/deallocation of the buffer. Effectively calls rdbuf()->pcount()

Contents

Notes

After a call to str(), dynamic streams become frozen automatically. A call to freeze(false) is required before exiting the scope in which this strstream object was created. otherwise the destructor will leak memory. Also, additional output to a frozen stream may be truncated once it reaches the end of the allocated buffer.

Parameters

flag - desired status

Return value

(none)

Example

#include <strstream>
#include <iostream>
 
int main()
{
    std::strstream dyn; // dynamically-allocated output buffer
    dyn << "Test: " << 1.23;
    std::cout << "The output stream contains \"" << dyn.str() << "\"\n";
 
    dyn << "Test: " << 1.23;
    std::cout << "The output stream contains \"" << dyn.str() << "\"\n";
    // the stream is now frozen due to str()
    dyn << " More text";
    std::cout << "The output stream contains \"" << dyn.str() << "\"\n";
    dyn.freeze(false);
}

Possible output:

The output stream contains "Test: 1.23"
The output stream contains "Test: 1.23 More "

See also

sets/clears the frozen state of the buffer
(public member function of std::strstreambuf) [edit]