Re: C++ in-class member initialization

From:
Victor Bazarov <v.bazarov@comcast.invalid>
Newsgroups:
comp.lang.c++
Date:
Tue, 17 May 2011 12:33:02 -0400
Message-ID:
<iqu7vv$v39$1@dont-email.me>
On 5/17/2011 10:25 AM, Syron wrote:

m_v2 will be 3 as Foo::Foo calls the parametrized (is that a word?)


Yes, it's a word. I usually put an extra 'e' after the 't'.

constructor of the in-class initializer class, whereas m_v1 will be
default-constructed. This allows default values with optional
initialization with other values.

Regarding the references: These are in my opinion pitfalls, as the
referenced data object may get destroyed while the referencing member
still exists - by the way, I think shared_ptr is much better for
referencing than using raw references as class members, but this is only
a side note and should not matter in this topic.

For the simple types: No, not only simple types, you could use every
type that supports either an implicit constructor [1] or a
copy-constructor [2], e.g.:
INCLASS_INIT(std::string, s1, "Hello"); // 1
INCLASS_INIT(std::string, s2, std::string("World")); // 2

And finally, the curly braces... I have tested my concept on FreeDOS
using DJGPP with only one single source file, this was only a
copy-and-paste of the inline declared constructor...

[hopefully this will not end as a top-posted reply, still haven't found a good news server]


That ended up as a free-standing post, not a reply to anything.
Nevertheless, thanks for taking time to reply.

So, all that elaborate mechanism is to avoid putting those members in
the initialization list[s] with given values? <shrug>

When I said "simple types", I meant types that [usually] support those
c-tors you've named (implicit c-tor, copy c-tor). IOW, not for any type
I can imagine. Again, <shrug>.

You still haven't answered my question: what's the point? What problem
were you solving?

V
--
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