Stable Numerics Subroutine Library
Programming Reference Manual
Version 1.0 DD-00006-010
6.3.5 Comparison Operators
bool operator==(const rc_interval<T>& o) const;
bool operator!=(const rc_interval<T>& o) const;

These operators check for equality or inequality to another rc_interval<T> instance. This is done by set comparison of the real and imaginary component intervals.