virtual int overflow(int c = EOF);
If c !=
EOF
, the protected virtual member function endeavors to insert the element (char)c
into the output buffer. It
can do so in various ways:
- If a write position is available, it can store the element into the write position and increment the next pointer for
the output buffer.
- If the stored strstreambuf mode says the controlled sequence is modifiable, extendable, and not frozen, the
function can make a write position available by allocating new for the output buffer. (Extending the output buffer
this way also extends any associated input buffer.)
If the function cannot succeed, it returns EOF
. Otherwise, if c == EOF
it returns some value other than EOF
. Otherwise,
it returns c
.