Inherited from basic_file.
Alter the size of the file.
void resize( uint64_t n, boost::system::error_code & ec);
This function resizes the file to the specified size, in bytes. If the
current file size exceeds
then any extra data is discarded. If the current size is less than
n then the file is extended and filled
The new size for the file.
Set to indicate what error occurred, if any.