Re:[boost] [serialization] scoped_ptr.hpp broken
Vladimir wrote:
......./boost/boost/serialization/scoped_ptr.hpp:36: error: `make_nvp' undeclared (first use this function)
The attached patch fixes the problem.
BTW, Robert, this problem was introduce when you moved the content of the header from boost::serialization to just boost::. What was the rationale? The log only says:
fixes for cw/comeau implement ADL
This was changed in order to function with compilers that implement two-phase lookup. This is described (somewhat) in them manual under the section:Reference/Class Serialization/Free Functions/Namespaces for Free Function Overrides Before this change, there is a problem with compilers which implement two-phase lookup. Overrides for templates have to be defined before their usage in another template. This conflicted with the implementation of BOOST_CLASS_EXPORT. To support these compilers, I had to either put non-intrusive serialization functions in the same namespace as the type being serialized or re-organize export. The latter is non-trivial and couldn't be guaranteed to be ready in time for release (at least at the time the issue came up). Perhaps, export may someday get re-organized so that BOOST_CLASS_EXPORT can appear before the archive classes which would resolve the problem in a simpler way. But for now - that's the way it is. Robert Ramey
Hi Robert,
Vladimir wrote:
......./boost/boost/serialization/scoped_ptr.hpp:36: error: `make_nvp' undeclared (first use this function)
The attached patch fixes the problem.
BTW, Robert, this problem was introduce when you moved the content of the header from boost::serialization to just boost::. What was the rationale? The log only says:
fixes for cw/comeau implement ADL
This was changed in order to function with compilers that implement two-phase lookup. This is described (somewhat) in them manual under the section:Reference/Class Serialization/Free Functions/Namespaces for Free Function Overrides
I think the docs are a bit unclear: The question arises as to which namespace free serialization functions should be part of. The options for this depend on: Whether or not the compiler implements Argument Dependent Lookup. whether (***** 'or' missing?)not the compiler implements Two Phase Lookup whether or (**** 'not' missing?) the the type to be serialized is a dependent type. What's the meaning of 'dependent' type? Do you mean 'dependent in context of 'serialize'? Then, if I write: template<class Archive> inline void serialize( Archive & ar, my_class & t, const unsigned long int file_version) {} then the type to be serialized is never dependent type. Or do you refer to a case where 'serialize' is templated on saved type? I'd suggest that you write that explicitly, as "dependent type" is a bit vague.
Before this change, there is a problem with compilers which implement two-phase lookup. Overrides for templates have to be defined before their usage in another template.
It would be great if you could put the explanation to the docs. BTW, I start to wonder if two-phase lookup does any good, for all additional portability problems that it has.
This conflicted with the implementation of BOOST_CLASS_EXPORT. To support these compilers, I had to either put non-intrusive serialization functions in the same namespace as the type being serialized or re-organize export. The latter is non-trivial and couldn't be guaranteed to be ready in time for release (at least at the time the issue came up).
Is the issue really with BOOST_CLASS_EXPORT? It seems that on compilers with two-phase lookup, if 'save' overloads are in boost::serialization, they must be seen before any code which uses 'save'. And this requirement is not specific to BOOST_CLASS_EXPORT. And also, btw, the table says boost::serialization is suitable for 'save' overload if compiler supports ADL, two-phase lookup and type is dependent. Why is it so? - Volodya
participants (2)
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Robert Ramey -
Vladimir Prus