Created on 2021-02-04.00:00:00 last changed 27 months ago
Proposed resolution (April, 2021):
Change 11.4.5.3 [class.copy.ctor] paragraph 6 as follows:
If the class definition does not explicitly declare a copy constructor, a non-explicit one is declared implicitly. If the class definition declares a move constructor or move assignment operator, the implicitly declared copy constructor is defined as deleted; otherwise, it isdefined asdefaulted (9.5 [dcl.fct.def]). The latter case is deprecated if the class has a user-declared copy assignment operator or a user-declared destructor (D.7 [depr.impldec]).
Change 11.4.6 [class.copy.assign] paragraph 2 as follows:
If the class definition does not explicitly declare a copy assignment operator, one is declared implicitly. If the class definition declares a move constructor or move assignment operator, the implicitly declared copy assignment operator is defined as deleted; otherwise, it isdefined asdefaulted (9.5 [dcl.fct.def]). The latter case is deprecated if the class has a user-declared copy constructor or a user-declared destructor (D.9). The implicitly-declared...
[Accepted as a DR at the June, 2021 meeting.]
According to 11.4.5.3 [class.copy.ctor] paragraph 6,
If the class definition does not explicitly declare a copy constructor, a non-explicit one is declared implicitly. If the class definition declares a move constructor or move assignment operator, the implicitly declared copy constructor is defined as deleted; otherwise, it is defined as defaulted (9.5 [dcl.fct.def]).
However, this rule is contradicted by paragraph 10, which lists a number of other reasons why a defaulted copy constructor will be defined as deleted, rather than being “defined as defaulted,” as required by paragraph 6:
A defaulted copy/move constructor for a class X is defined as deleted (9.5.3 [dcl.fct.def.delete]) if X has:
...
A similar contradiction exists for copy assignment operators in 11.4.6 [class.copy.assign] paragraphs 2 and 7.
History | |||
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Date | User | Action | Args |
2022-08-19 07:54:33 | admin | set | status: drwp -> cd6 |
2021-11-15 00:00:00 | admin | set | messages: + msg6594 |
2021-11-15 00:00:00 | admin | set | status: open -> drwp |
2021-02-04 00:00:00 | admin | create |