The Fortress Language Specification - CiteSeerX

10.4 Object Equivalence
The trait Object defines the object equivalence operator = . This operator is automatically defined for all objects;
it is a static error for the programmer to override it. The = operator is used to decide whether its two arguments
refer to “the same object” in the strictest sense possible. If the arguments have different dynamic types—including the
instantiations of all static parameters—the result is always false . If both arguments are value objects with the same
type, then the result is true if and only if corresponding fields of the objects are themselves equivalent as defined by
this operator; in particular, two binary words are strictly equivalent if and only if they contain the same bit pattern. If
both arguments are object references, then the result is true if and only if the two object references refer to the identical
reference object (in implementation terms, occupying the same memory locations in the heap). If both arguments are
functions, the result is true only if the functions behave identically for any choice of type-correct arguments. Even if
two functions behave identically, the fortress implementation is free to return false when they are compared for object
equivalence.
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