Re: sizetest.ads:10:28 non-static expression used in number declaration

["Frank J. Lhota" <NOSPAM.FrankLho@rcn.com>]

A number declaration must use a static expression. The ARM gives a very
strict definition of when a subtype is considered static: it must be a
static scalar subtype, or a static string subtype (see 4.9, paragraph 26).
Foo, being a record type, is not static.

This criteria for static subtypes may seem to be overly strict. It is
difficult, however, to devise a more comprehensive definition of static
subtype without getting into a lot of complexities. As you have noted, the
problem can be avoided by defining Foo_Size to be a constant integer, rather
than a named number. The expression used to initialize a constant need not
be static.

A related issue: enumeration literals are static, but renamed enumeration
literals are not. Hence if I declare

    function Yes return Boolean renames True;

then True is static, but Yes is not. Frankly, I find this annoying.