* mdlinux7@[EMAIL PROTECTED]
> Best way to get inside C++ is to read C++ standards. Inspite of four
> years of experience, I get confused reading C++ standard.
>
> I could not understand the below paragraph $14.2
>
> Note: in a class template declaration, if the declarator-id is a
> template-id, the declaration declares a class template partial
> specialization
>
> A template specialization (_temp.spec_) can be referred to by a
> template-id:
>
> How could we justify the $14.2 paragraph in below example
> template<class T1, class T2, int I> class A { }; // #1
> template<class T, int I> class A<T, T*, I> { }; // #2
> partial specialization
>
> What will be declaration-id in above case ?
First of all, you're really discussing §14/2 (second paragraph of main
section fourteen), not §14.2.
For a declaration of a class without any template stuff involved, the
'declarator-id' is just the (possibly qualified) class name, and in the
case above it's what plays the role of that simple class name, namely
the 'A<T,T*,I>'.
> As per my understanding, template-id will be class A<T,T*,I>.
No, it will be just 'A<T,T*,I>'.
Shown here in a more usenet-friendly notation than the standard's,
'declarator-id' is defined by §8/4 as
declarator-id ::= id-expression
declarator-id ::= "::"(opt) nested-name-specified(opt) type-name
'id-expression' is defined by §5.1/1 as
id-expression ::= unqualified-id
id-expression ::= qualified-id
'qualified-id' is defined by §5.1/7 as (I imply line continuation by \)
qualified-id ::= "::"(opt) nested-name-specifier "template"(opt) \
unqualified-id
qualified-id ::= identifier
qualified-id ::= operator-function-id
qualified-id ::= template-id
Interestingly, 'template-id' is defined by §14.2 -- the place you
indicated but not what you actually referred to! -- as
template-id ::= template-name "<" template-argument-list(opt) ">"
Summing up so far,
declarator-id ::= id-expression ::= qualified-id ::= template-id
That's the connection between 'declarator-id' and 'template-id', and to
find the 'declarator-id' part of a declaration you'll have to nest in
the opposite direction from §8.4's definition, namely the context a
'declarator-id' can appear in, the role it plays in a class declaration
(as I explained first of all, informally). Btw., I have found that to
search in Adobe Acrobat, it's a good idea to leave out hyphens. E.g.,
search for 'declaratorid' instead of searching for 'declarator-id'.
> It gets difficult to understand keywords like declaration-id in C++
> standard. Is there any better way to understand C++ standards
It might be useful to buy a book on templates. As I understand it
Josuttis wrote a good one. Also, see my search tip above.
> as I want to get hold of each line quoted in standards.
?
--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
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