ISO/IEC 1539-1:2023/Cor 1:2026

International
Standard
ISO/IEC 1539-1
Fifth edition
Programming languages —
2023-11
Fortran —
TECHNICAL
Part 1:
CORRIGENDUM 1
Base language
2026-01
TECHNICAL CORRIGENDUM 1
Langages de programmation — Fortran —
Partie 1: Langage de base
RECTIFICATIF TECHNIQUE 1
Reference number
ISO/IEC 1539-1:2023/Cor. 1:2026(en) © ISO/IEC 2026

ISO/IEC 1539-1:2023/Cor. 1:2026(en)
© ISO/IEC 2026
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© ISO/IEC 2026 – All rights reserved
ii
ISO/IEC 1539-1:2023/Cor.1:2026(en)

Technical Corrigendum 1 to ISO/IEC 1539-1:2023 was prepared by Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 22, Programming languages, their environments and system software
interfaces.
© ISO/IEC 2026 – All rights
iv
ISO/IEC 1539-1:2023/Cor.1:2026(en)
International Standard ISO/IEC 1539-1:2023/Cor.1:2026(en)
Programming languages — Fortran —
Part 1: Base language
TECHNICAL CORRIGENDUM 1
Introduction
In the second paragraph, at the end of bullet point “Intrinsic modules”, append the sentence:
The result of the function IEEE_SCALB from the intrinsic module IEEE_ARITHMETIC has been
corrected to conform to the IEEE standard.
In the second paragraph, at the end of bullet point “Changes to the intrinsic module IEEE_ARITHMETIC for
conformance with ISO/IEC 60559:2020”, append the sentence:
The function IEEE_SCALB from the intrinsic module IEEE_ARITHMETIC now performs the scaleB
operation.
Subclause 4.3.3
After the fourth paragraph of the subclause, insert a new paragraph:
Fortran 2018 permitted a component-data-source in a structure constructor to be a coindexed
object with a pointer subcomponent. This document does not permit such usage.
In the fifth paragraph of the subclause, append a new bullet point:
• The result of a reference to the function IEEE_SCALB from the intrinsic module
IEEE_ARITHMETIC has been corrected to return the representable number having a
I I
magnitude nearest to |X × 2 | with the same sign as X, if X × 2 is too small to be represented
with full accuracy.
Subclause 4.3.4
After the fourteenth paragraph of the subclause, insert the following new paragraph:
Fortran 2008 permitted a component-data-source in a structure constructor to be a coindexed
object with a pointer subcomponent. This document does not permit such usage.
In the final (fifteenth) paragraph of the subclause, append a new bullet point with text identical to the
new bullet point in subclause 4.3.3.
Subclause 4.3.5
In the final (thirteenth) paragraph of the subclause, append a new bullet point with text identical to
the new bullet point in subclause 4.3.3.
Subclause 5.4.7
© ISO/IEC 2026 – All rights reserved
ISO/IEC 1539-1:2023/Cor.1:2026(en)
In the third paragraph of the subclause, change “For each coarray” to “For each established coarray”.
After “in which it is established (5.4.8).”, insert the new sentence:

For each unallocated coarray, there exists a corresponding unallocated coarray with the same
declared type, rank, corank, and non-deferred type parameters on each active image of the
current team.
Insert a new paragraph in between the above insertion and the rest of what was the third paragraph:

For a named coarray that is not a dummy argument, its corresponding coarrays are the ones with the
same name in that scoping unit. For a coarray that is a component at any level of component selection,
its corresponding coarrays are the same components of the base object that has the same name in
that scoping unit. If a coarray component is a potential subobject component of an array element, the
array element for its corresponding coarrays has the same position in array element order on each
image.
In the fourth paragraph of the subclause, after “The set of corresponding” insert “established”,
making the whole sentence read:

The set of corresponding established coarrays on all images in a team is arranged in a
rectangular pattern.
Subclause 7.5.4.1
Delete constraint C753 which begins “C753  A data component whose type has a coarray”.

After NOTE 1 insert new NOTE 2 and renumber subsequent NOTE.

NOTE 2 A data component whose type has a coarray potential subobject component cannot
be a coarray or a pointer, see constraint C825.

Subclause 7.5.10
In the first paragraph of the subclause, after the penultimate constraint C7109, insert new constraint:

C7109a (R758) If expr is a coindexed object, it shall not have a pointer
component at any level of component selection.

After NOTE 1, insert new NOTE 2 and renumber subsequent NOTEs:

NOTE 2 Although a coindexed object with a pointer subcomponent is not the only way for the
structure constructor to produce a value with an undefined pointer subcomponent, copying a pointer
from another image is particularly likely to cause undiagnosed incorrect results, and thus precluded
in this context.
Subclause 7.6.1
In the first paragraph of the subclause, in rule 762, after

R762 enumerator is named-constant [ = scalar-int-constant-expr ]

insert:
or named-constant [ = boz-literal-constant ]

In the sixth paragraph of the subclause, in the numbered list following “The enumerator is a scalar name
...