AMDG Alexander Nasonov <alnsn <at> yandex.ru> writes:
Steven Watanabe <watanabesj <at> gmail.com> writes:
AMDG
After 6+ months I've finally gotten back to this. I'd like to get some feedback on my ideas before I continue. The current version is in the vault.
The basic interface is derived from Alexander Nasonov's dynamic_any
Steven, I'm reading your code but there are 53 files full of meta-programming and reading them may take some time. Can you please give an overview of the implementation or highlight differences between your code and mine?
Biggest implementation difference: I am using an explicit table of function pointers and a separate buffer rather than a virtual functions. All the metaprogramming is either for creating the table or figuring out how one table maps onto another. At the lowest level, I have two components: a) a buffer class that handles allocation/deallocation or the small object optimization. (detail/anything.hpp) b) A generic vtable that supports static initialization and table conversions. (this is in detail/table/*) There are two distinct versions of function calls. The first has a fixed return type. The second returns another polymorphic object. The version that returns an any<>, takes a pointer to a buffer as a parameter and constructs the result in it. The table of the result is managed from outside the function call. This implies that the dynamic type of the result is entirely determined by the dynamic types of the arguments. The advantage of this is that conversions between any<>s work smoothly. (The code for mapping the interface onto a set of function pointers is in concept.hpp, detail/dispatch/*) detail/metafunction just contains some utilities that I needed and one important file that probably belongs elsewhere: type_deduction.hpp. This file has the code for working out what types each of the placeholders represent. e.g. If you have an any<function_call<_1()> > and construct it from a boost::function<int()> then _ will map to boost::function<int()> and _1 will map to _1. It handles the related case of mapping placeholders to placeholders for a conversion. In Christ, Steven Watanabe