Re: [boost] [constrained_value] serialization

Subject: Re: [boost] [constrained_value] serialization
From: OvermindDL1 (overminddl1_at_[hidden])
Date: 2008-12-15 19:25:11

On Sun, Dec 14, 2008 at 11:58 AM, Robert Kawulak
<robert.kawulak_at_[hidden]> wrote:
>> From: Neal Becker
>> >> constrained_value does not currently support serialization.
>> >> 1. Should it be added to the lib?
>> >> 2. What would be a suggested implementation?
>
> The implementation for general case seems a bit tricky, because some constrained
> objects (e.g., bounded_int<int, 1, 10>::type) should not be default-constructed
> by the Serialization library. Therefore, if I understand correctly,
> load_construct_data() /save_construct_data() should be overloaded rather than
> serialize() provided (but I'm not sure about this, I haven't used Serialization
> library).
>
>> > Good questions. As to the second, would it be sensible to
>> serialise the
>> > value + each of the policies that is non-empty (or
>> stateless)? Detection
>> > of class emptiness (statelessness) is not working with all
>> compilers, so
>> > this would possibly be a non-portable solution. But
>> otherwise users would
>> > need to provide serialization support for each empty policy too.
>> >
>> Is it feasible to have the user select which policies to serialize?
>
> Possibly by specialising non-member serialize() / load_construct_data()
> /save_construct_data()?

What about another optional template parameter for a
default-construction value for the object (either an already instanced
value, or a function/functor to build one or something)?  Less hassle
in many cases then, and would allow default construction of any of
those that are by default not default constructable.