Size of stringstream [duplicate]

There is:

std::stringstream oss("Foo");
oss.seekg(0, ios::end);
int size = oss.tellg();

Now, size will contain the size (in bytes) of the string.

EDIT:

This is also a good idea to put after the above snippet as it puts the internal pointer back to the beginning of the string.

oss.seekg(0, ios::beg);