Assign to this object the value of the specified rhs, and return a reference providing modifiable access to this object. The contents of rhs are move-assigned to this object. rhs is left in a valid but unspecified state.
Declared in <bslstl_istringstream.h>
basic_istringstream<CHAR_TYPE, CHAR_TRAITS, ALLOCATOR>&
operator=(basic_istringstream&& rhs);