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Subject: [boost] [convert] Now with Boost.Parameter interface.
From: Vladimir.Batov_at_[hidden]
Date: 2009-05-04 00:12:10

I've incorporated, uploaded to the Vault and started playing with the
Boost.Parameter-based interface that Andrey Semashev was insisting from
the set-go. And it is definitely growing on me and I like

        int i = convert<int>::from(str, 0)(locale_ = new_locale)(throw_ =

instead of the original

        int i = convert<int>::from(str, 0) >> new_locale >> dothrow;

I think people generally did not like locales and dothrow behaving like

The more I use the Boost.Parameter-based interface the more I am inclined
to push it further and apply it to manipulators as well. I.e.

        int i = convert<int>::from(str)(radix_ = 16);

instead of the original direct handling of std manipulators.

        int i = convert<int>::from(str) >> std::hex;

Something, again, Andrey was advocating from the start. Now it feels like
allowing io-stream manipulators exposes too much implementation detail and
raises some unwarranted expectations.

That raises a few questions that I am hoping people could help me with:

1. Both interfaces (for locale and dothrow) are currently supported:

#1 int i = convert<int>::from(str, 0)(locale_ = new_locale)(throw_
= true);
#2 int i = convert<int>::from(str, 0) >> new_locale >> dothrow;

Should I remove #1?

2. Both interfaces

#1 int i = convert<int>::from(str, 0) >> std::hex;
#2 int i = convert<int>::from(str, 0)(radix_ = 16);

are currently supported. Should I move away from direct manipulator
support and remove #1?

3. I only managed to figure out how to supply only one Boost.Parameter at
a time like

        int i = convert<int>::from(str, 0)(locale_ = new_locale)(throw_ =

I understand how to achieve

        int i = convert<int>::from(str, 0)((locale_ = new_locale, throw_ =

(with double quotes) but do not want to go there as it looks somewhat
unorthodox. I cannot figure out how to achieve the following

        int i = convert<int>::from(str, 0)(locale_ = new_locale, throw_ =

(a list inside single quotes). I remember Andrey mentioning I could do
that with a Boost.Parameter macro but I admit of not being bright enough
to figure it out by myself. Any help would be greatly appreciated.


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