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.
注意
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