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Subject: Re: [boost] [TTI] Review
From: lcaminiti (lorcaminiti_at_[hidden])
Date: 2011-07-11 17:17:11

Edward Diener-3 wrote:
> On 7/11/2011 10:56 AM, Stewart, Robert wrote:
>> Edward Diener wrote:
>>> On 7/10/2011 7:59 PM, Lorenzo Caminiti wrote:
>>>> Review of Boost.TTI 2011-07-10 (Lorenzo Caminiti)
>>>> 10. [NOTE] I think "member variable" is a more accepted name
>>>> that "member data"-- isn't it? If so, I'd rename MEMBER_DATA
>>> I can understand your preference. I will consider it.
>> They are called data members, not member variables, in C++. Names like
>> "member variable" come from other languages.
>> I don't use "member data" generally, but to me it describes data members
>> collectively, not singularly.
>> I recognize the desire to keep the prefixes alike, but I'd rather see
>> "HAS_DATA_MEMBER" to be consistent with Standard terminology.
> I agree with your remark about the normal terminology. I could have used
> HAS_DATA_MEMBER and HAS_MEMBER_FUNCTION but I wanted to align the names
> around a common beginning. That is why I chose HAS_MEMBER_DATA and
> HAS_STATIC_MEMBER_FUNCTION. Sometimes such mnemonic similarities (
> having the same common beginnings ) is more important than other factors.
> I know that this may start some long discussion about names in TTI, but
> here is a general suggestion to all programmers who are ever upset about
> names in a library, and does not just refer to TTI: if you do not like a
> name, just create an object-like macro for your own use which takes some
> name and transforms it to some other name which you like better.
> Lorenzo might write the macro:
> and you might write the macro:
> This is guaranteed to work without problems all the time AFAIK to
> transform one name to another.

My comment #10 started by asking if member variable is the common name. As
it has been pointed out, it is not. From Stroustrup C.12 (page 853) "data
member" is the common name so I think MEMBER_DATA is the appropriate name
and the one I would like to use (this discussion is about the name that the
C++ standard uses, not the name I like).

BTW, still from Stroustrup C.12 (page 853) there exist a composite form from
data members, not just member functions:

typedef void (C::* member_func_type)(int);
typedef const char* C::* member_var_type;

So back to my comment #11, I would like to see:

    TTI_MEMBER_DATA(has_number, number)

    has_number<int T::*> // [1]

Instead of:

    has_number&lt;T, int&gt; [2]

Again, I would only provide the composite form for checking member functions
(my comment #9) and for consistency I would only provide [1] (not [2]) for
data members (my comment #11).


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