Callsfreeze(), then returns a copy of start pointer of the get area,std::streambuf::eback().

The start of the get area, for all writeablestd::strstreambuf objects constructed through the interface provided bystd::strstream, is also the start of the put area.

[edit]Parameters

(none)

[edit]Return value

A copy ofeback(), which may be a null pointer.

[edit]Notes

This function is typically called through thestd::strstream interface.

The call tofreeze() guarantees that the returned pointer remains valid until the next explicit call tofreeze(false): otherwise (on a dynamic buffer) any output operation could trigger buffer reallocation which would invalidate the pointer. It also causes a memory leak in the destructor ofstd::strstreambuf, unlessfreeze(false) is called before the buffer (or, more commonly, thestd::strstream that manages it) is destroyed.

[edit]Example

#include <iostream>#include <strstream> int main(){std::strstream dyn;// dynamically-allocated read/write buffer    dyn<<"Test: "<<1.23<<std::ends;std::strstreambuf* buf= dyn.rdbuf();std::cout<<"R/W buffer holds ["<< buf->str()// or dyn.str()<<"]\n";    dyn.freeze(false);// after calling .str() on a dynamic strstream char arr[10];std::ostrstream user(arr,10);// fixed-size write-only buffer    buf= user.rdbuf();    user<<1.23<<std::ends;std::cout<<"Write-only buffer holds ["<< buf->str()// or user.str()<<"]\n"; std::istrstream lit("1 2 3");// fixed-size read-only buffer    buf= lit.rdbuf();std::cout<<"Read-only buffer holds ["<< buf->str()// or lit.str()<<"]\n";}

R/W buffer holds [Test: 1.23]Write-only buffer holds [1.23]Read-only buffer holds [1 2 31 2 3]

[edit]See also

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