Proposed resolution:

This wording is relative to N4910.

1. Modify [container.reqmts] as indicated:

   X u;
   X u = X();
   

   -10- Postconditions: !u.empty() for array<T, N> where 0 < N, and u.empty() for all other standard containers.

   -11- Complexity: ConstantLinear for array<T, N> where 0 < N and constant for all other standard containers.

   […]

   X u(rv);
   X u = rv;
   

   -15- Postconditions: u is equal to the value that rv had before this construction.

   -11- Complexity: Linear for array<T, N> where 0 < N and constant for all other standard containers.

   […]

   a.swap(b)
   

   -45- Result: void

   -46- Effects: Exchanges the contents of a and b.

   -47- Complexity: Linear for array<T, N> where 0 < N and constant for all other standard containers.

2. Modify [array.overview] as indicated:

   -2- An array is an aggregate ([dcl.init.aggr]) that can be list-initialized with up to N elements whose types are convertible to T.

   -3- An array<T, 0> meets all of the requirements of a container ([container.reqmts]) and of a reversible container ([container.rev.reqmts]). An array<T, N> where 0 < N meets all of the requirements of a container ([container.reqmts]) and of a reversible container ([container.rev.reqmts]), except that a default constructed array<T, N> object is not empty if N > 0 and default construction, move construction, and swap have linear complexity if N > 0. An array meets some of the requirements of a sequence container ([sequence.reqmts]). Descriptions are provided here only for operations on array that are not described in one of these tables and for operations where there is additional semantic information.

[ 2022-04-24; Daniel rebases wording on N4910 ]

[ 2019-07 Issue Prioritization ]

Priority to 3 after discussion on the reflector.

Previous resolution [SUPERSEDED]:

This wording is relative to N4810.

1. Modify [container.requirements.general], Table 62 — "Container requirements", as indicated (This table can be identified by the "section" identifier [tab:container.req] in the next working draft):

   Table 62 — Container requirements

   Expression	Return type	Operational semantics	Assertion/note pre/post-condition	Complexity
   […]
   X u;			Ensures: !u.empty() for array<T, N> where 0 < N, and Ensures: u.empty() for all other standard containers.	constant(Note A)
   X()			Ensures: !X().empty() for array<T, N> where 0 < N, and Ensures: X().empty() for all other standard containers.	constant(Note A)
   […]

   Those entries marked "(Note A)" or "(Note B)" have linear complexity for array<T, N> where 0 < N and have constant complexity for all other standard containers.

2. Modify [array.overview] as indicated:

   -2- An array is an aggregate ([dcl.init.aggr]) that can be list-initialized with up to N elements whose types are convertible to T.

   -3- An array<T, 0> satisfies all of the requirements of a container and of a reversible container ([container.requirements]). An array<T, N> where 0 < N satisfies all of the requirements of a container and of a reversible container ([container.requirements]), except that a default constructed array<T, N> object is not empty and thatboth default construction and swap does not have constantlinear complexity. An array satisfies some of the requirements of a sequence container ([sequence.reqmts]). Descriptions are provided here only for operations on array that are not described in one of these tables and for operations where there is additional semantic information.

The requirements specified in [array.overview] p3 are incorrect; namely:

• A default constructed array<T, N> where 0 < N has linear, not constant complexity.

• A default constructed array<T, 0> is empty and has constant complexity.