Re: [Boost-users] Serialization with pointer to const object

Emil Dotchevski wrote:

On Fri, Jul 24, 2009 at 4:40 PM, Robert Ramey wrote:

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Emil Dotchevski wrote:

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IMO even after the serialization library dereferences the pointer-to-const, it should const_cast it to serialize the object, because in the typical case the object is mutable. For example, if you have:

int const * p=new int(42);

So p->member of p should fail to compiler while ar << p should?

Doesn't make sense to me. I think it's a very bad idea to try to make things "just work" when it means changing the behavior from what is written to what one would think is a " rather safe bet".

Probably the reason why it doesn't make sense to you but it makes sense to me is that you're looking at serializing a pointer as a mutable operation on the pointee, whereas I look at it as a mutable operation on the pointer itself.

Please don't get me wrong, I wouldn't want the following code to compile:

struct foo { int const m_x; };

.... ar << a_foo.m_x;

But I think that the code below should just work:

struct foo { int const * m_x; };

Maybe - now that I think about it. the library creates a NEW object when it loads a pointer so one could argue that the "const" isn't being violated. An alternative interpretation of "serialization" would have been that ar >> m_x would be equivalent to ar >> *m_x in which case the "const" would be violated. Also the issue comes up with wrappers as well. xml, binary object. Truth is, I never really thought about this in systematic way and just sort of applied it on a case by case basis as I went along. Someday I'll look at it more carefully.

.... ar << a_foo.m_x;

Emil Dotchevski Reverge Studios, Inc. http://www.revergestudios.com/reblog/index.php?n=ReCode