From cppreference.com
voidfreeze(boolfreezefl=true);(deprecated in C++98)
(removed in C++26)If the buffer uses dynamic allocation, sets the frozen status of the stream to freezefl.
While the stream is frozen,
will not reallocate the buffer and the
will not deallocate the buffer (thereby causing a memory leak).
Parameters
freezefl - new value to set the freeze status to Return value
(none)
Notes
Every call to
freezes the stream to preserve the validity of the pointer it returns. To allow the destructor to deallocate the buffer, freeze(false) needs to be called explicitly.
Example
In this example, initial allocation of the underlying array was for 16 bytes.
Run this code
#include<iostream>#include<strstream>intmain(){{std::strstreamdyn;// dynamically-allocated read/write bufferdyn<<"Test: "<<1.23;// note: no std::ends to demonstrate append behaviorstd::cout<<"dynamic buffer holds "<<dyn.pcount()<<" characters: '";std::cout.write(dyn.str(),dyn.pcount())<<"'\n";// the buffer is now frozen, further output will not make the buffer growdyn<<"more output, hopefully enough to run out of the allocated space"<<std::ends;std::cout<<"After more output, it holds "<<dyn.pcount()<<" characters: '"<<dyn.str()<<"'\n";dyn.freeze(false);// unfreeze before destructor}// memory freed by the destructor{chararr[20];std::ostrstreamst(arr,sizeofarr);// fixed-size bufferst<<1.23;// note: no std::ends to demonstrate append behaviorstd::cout<<"static buffer holds "<<st.pcount()<<" characters: '";std::cout.write(st.str(),st.pcount());std::cout<<"'\n";st<<"more output, hopefully enough to run out of the allocated space"<<std::ends;std::cout<<"static buffer holds "<<st.pcount()<<" characters: '";std::cout.write(st.str(),st.pcount());std::cout<<"'\n";}// nothing to deallocate, no need to unfreeze,}Output:
dynamic buffer holds 10 characters: 'Test: 1.23' After more output, it holds 16 characters: 'Test: 1.23more o' static buffer holds 4 characters: '1.23' static buffer holds 20 characters: '1.23more output, hop' See also
disables/enables automatic reallocation
(public member function of std::strstream)
disables/enables automatic reallocation
(public member function of std::ostrstream)
[virtual]
destructs a strstreambuf object, optionally deallocating the character array
(virtual public member function)
[virtual]
appends a character to the output sequence, may reallocate or initially allocate the buffer if dynamic and not frozen
(virtual protected member function)