To: J3                                                     J3/19-213
From: Bill Long
Subject: US-23 Part 3, BITS type
Date: 2019-August-08
Reference: 19-159

Discussion:
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This paper describes Part 3 (of 3) of the BITS proposal, US-23. This
would be adopted as an alternative to Part 2, as it would encompass
all of the requirements of Part 2.

The full BITS proposal is for a new BITS data type with conversion to
numeric types. It is a comprehensive provision of a BITS type and bit
manipulation in Fortran.

The advantage of this alternative is that the edits for all of the
feature (except for Part 1 of the US-23 proposal) have been written
and debugged previously as part of drafts of the Fortran 2008
standard.  Additionally, it provides a more complete BITS capability
for Fortran.

The disadvantage of Part 3 is that it is a significantly larger
feature than Part 2, both in terms of modifications to the standard
and compiler implementation effort. While the edits to the standard
are "known" they are numerous and would be labor intensive.


Sematics and Syntax
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See J3 paper 19-159.

Edits to 18-007r1
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(to be supplied)