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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Representation clauses and records
Date: 1997/11/25
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Martin says

<<also, from what i remember, there is no obligation on a compiler vendor
to actual 'do' anything with a predefinde pragma other than recognise
it. why not 'for space_optimized_array_type'size use space_optimised_arr
ay_element'storage_size'?..
>>

No, you remember wrong (or perhaps you are trying to remember Ada 83). In
Ada 95, if annex C is supported, pragma Pack very definitely cannot be
ignored. The exact rules for what it must support are clear in the RM.

There is some implementation dependence, to be sure. For example, packing
2 bit quantities must be tight, but packing 3 bit quantities can either
be tight, or use 4 bits/element on a typical machine.