Bug 10549 – Default object equality test not properly implemented

In the base object class ("Object") the opEquals overload (which is inherited as the default EqualExpression operation for objects) does not appear to be implemented the way it is described. The function is defined in object_.d (http://github.com/D-Programming-Language/druntime/blob/master/src/object_.d) as this: /** * Returns !=0 if this object does have the same contents as obj. */ bool opEquals(Object o) { return this is o; } (I'm not exactly sure what "!=0" is supposed to mean there, but I'll take it to mean "true"). As I understand it, the "is" operator tests whether two object references refer to the same instance, not whether "this object does have the same contents as obj". This also contradicts the official description of EqualExpression (http://dlang.org/expression.html#EqualExpression): "For class objects, the == and != operators compare the contents of the objects." Clearly, this functionality is not satisfied by an IdentityExpression. Perhaps something like "this.tupleof == o.tupleof" would be more appropriate?

this is really a documentation issue; pull request: https://github.com/dlang/dlang.org/pull/1441

Commit pushed to master at https://github.com/dlang/dlang.org https://github.com/dlang/dlang.org/commit/cbd6d46b0034eb0b4757c693a71566d64d19a850 default opEquals does not compare object contents this documents the behaviour more clearly, addressing issue 10549

Commit pushed to stable at https://github.com/dlang/dlang.org https://github.com/dlang/dlang.org/commit/cbd6d46b0034eb0b4757c693a71566d64d19a850 default opEquals does not compare object contents