42 lines
1.0 KiB
C
42 lines
1.0 KiB
C
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#pragma once
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#include "detail/typelist.h"
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namespace mpm {
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namespace detail {
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/// root class for polymorphic event hierarchies
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class event {
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protected:
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//don't dispatch as this type - it's an internal
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//implementation detail
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using dispatch_as = null_t;
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virtual ~event() {}
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};
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/// forward decl from eventbus.h
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template<typename E>
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struct dispatch_typelist;
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}// namespace detail
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//! Publicly inherit from this class to obtain polymorphic
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//! event delivery.
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template<typename T, typename Base = detail::event>
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class enable_polymorphic_dispatch : public Base {
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protected:
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// \internal
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// Couldn't use a typelist based on std::tuple here because
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// std::tuple_cat won't work with an incomplete type, and the
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// derived event types are incomplete when decltype(tuple_cat)
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// would be used
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#ifdef DOCS
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using dispatch_as = implementation - defined;
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#else
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template<typename E>
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friend class detail::dispatch_typelist;
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using dispatch_as = detail::typelist<T, typename Base::dispatch_as>;
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#endif
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};
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}// namespace mpm
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