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Joe Gottman · Guest

[Note: Forwarded to C++ Committee. -sdc ]

According to the draft Technical Report on Standard Library Extensions,
two shared_ptr's are equivalent under the !(a < b) && !(b < a) relationship
if and only if they share ownership. But an empty (default constructed)
shared_ptr does not share ownership with anything, not even itself. This
means that if a is an empty shared_ptr, it will not be equivalent to itself,
so operator< is not a strict weak ordering. The same holds true for
weak_ptr's.

Suggested Resolution:

Change the specification of shared_ptr::operator<() to say two
shared_ptr's are equivalent if and only if they share ownership or are both
empty.

Change the specification of weak_ptr::operator<() to say two weak_ptr's
are equivalent if and only if they share ownership or are both empty.

Joe Gottman

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