DDSXTY_ — Definition of “strongly assignable” is incomplete

The definition of the term “strongly assignable” in section 7.2.4, Type Compatibility: “is-assignable-from” relationship, states:

If types T1 and T2 are both mutable and T1 is-assignable-from T2, then T1 is said to be “strongly” assignable from T2.

The purpose of this concept is to distinguish cases where it is possible to delimit adjacent objects. This is necessary, for example, when deserializing arrays, to avoid a situation where extra members in an array element could throw off the deserialization of subsequent elements.

This definition is overly restrictive and can even prevent arrays of non-mutable elements from being assignable to themselves.

Proposed Resolution:

Amend the definition to consider any type strongly assignable to itself.

Proposed Revised Text:

The definition of the term “strongly assignable” in section 7.2.4, Type Compatibility: “is-assignable-from” relationship, states:

If types T1 and T2 are both mutable and T1 is-assignable-from T2, then T1 is said to be “strongly” assignable from T2.

Append the following sentence:

Any type is also considered (trivially) strongly assignable from itself, regardless of its extensibility kind.

Amend the definition of “strongly assignable” to consider any type strongly assignable to itself