J3/14-229
To:      J3
From:    Nick Maclaren
Subject: Conformability and allocated components
Date: 2014 August 13

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NUMBER: TBD
TITLE: Conformability and allocated components
KEYWORD: Conformable, allocatable
DEFECT TYPE: Clarification
STATUS: J3 consideration in progress

QUESTION 1:

Are the objects one and two conformable after the allocation?

PROGRAM Main
    TYPE :: Mytype
        INTEGER, ALLOCATABLE :: data(:)
    END TYPE Mytype
    TYPE(Mytype) :: one, two
    ALLOCATE(one%data(3),two%data(5))
    ! Are one and two conformable?
END PROGRAM Main


QUESTION 2:

Are the objects one and two conformable after the allocation?

PROGRAM Main
    TYPE :: Mytype
        INTEGER, POINTER :: data(:)
    END TYPE Mytype
    TYPE(Mytype) :: one, two
    ALLOCATE(one%data(3),two%data(5))
    ! Are one and two conformable?
END PROGRAM Main


DISCUSSION:

There appears to be no precise definition of conformable.  1.3.35 says
that conformable is <of two data entities> having the same shape, ....
Unfortunately, that could be read either way for the above examples.

7.2.1.2p1(3) says "the variable and expr shall be conformable unless the
variable is an allocatable array that has the same rank as expr and is
neither a coarray nor a coindexed object".  7.2.1.3p13 describes
assignment of derived types, essentially to be recursive.  This would
seem to mean that they are not conformable in the first example, but
are in the second, but there is room for doubt.

A precise definition of conformable is needed.


ANSWER:

Awaiting statement of direction.


EDITS:

Awaiting statement of direction.


SUBMITTED BY: Nick Maclaren


HISTORY: m205   14-nnn   Submitted