sizeof() confusion

[Henry Spencer]

In article <1990Nov16.141352.22426 at dce.ie> ch at dce.ie (Charles Bryant) writes:
>> there are two distinct uses of sizeof:
>>	sizeof unary_expression
>>	sizeof ( type_name )
>
>That must make parsing it more difficult than if the parentheses were always
>required:
>	sizeof (type_name) - 1
>since in other contexts "(type_name) - 1" would be an expression containing
>a cast.

Requiring parentheses wouldn't make any difference, since it's still legal
to wrap a unary expression in parentheses, so you can't tell from the
opening parenthesis which form is coming.  What *would* be useful is if
casts began with something that *couldn't* begin a unary expression.
As it is, either you need to sneak a peek a bit further ahead, or you
get to write some contorted code that swallows the parenthesis and then
decides, based on the next token, whether it has cast-minus-leading-paren
or parenthesized-expression-minus-leading-paren.  Definitely a nuisance,
and it's not the only such case in C.
-- 
"I don't *want* to be normal!"         | Henry Spencer at U of Toronto Zoology
"Not to worry."                        |  henry at zoo.toronto.edu   utzoo!henry