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78 lines
1.6 KiB
Plaintext
78 lines
1.6 KiB
Plaintext
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## rtti
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### Synopsis
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Defined in <boost/openmethod/policies/basic_policy.hpp>.
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```c++
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namespace boost::openmethod::policies {
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struct rtti : policy {};
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} // boost::openmethod::policies
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```
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### Description
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The `rtti` policy provides type information for classes and objects, implements
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downcast in presence of virtual inheritance, and writes descriptions of types to
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an `ostream`-like object.
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### Requirements
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#### is_polymorphic
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```c++
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template<class Class> static constexpr bool is_polymorphic;
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```
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`true` if `Class` is polymorphic.
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#### static_type
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```c++
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template<class Class> static auto static_type() -> type_id;
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```
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Returns a `type_id` for `Class`.
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#### dynamic_type
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```c++
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template<class Class> static auto dynamic_type(const Class& obj) -> type_id;
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```
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Returns a `type_id` for an object's dynamic type.
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#### type_name
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```c++
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template<typename Stream>
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static auto type_name(type_id type, Stream& stream) -> void;
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```
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Writes a description of `type` to `stream`.
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This requirement is optional. `rtti` provides a default implementation that writes `typeid({type})` to `stream`.
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#### type_index
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```c++
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static auto type_index(type_id type) -> /* unspecified */;
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```
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Returns a unique key for `type`. Required only for RTTI systems that assign more
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than one type "identifiers" to a type. For example, standard RTTI allows
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implementations to have multiple instances of `std::type_info` for the same
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type.
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#### dynamic_cast_ref
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```c++
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template<typename D, typename B>
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static auto dynamic_cast_ref(B&& obj) -> D;
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```
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Casts `obj` to `D`. Required only if using virtual inheritance.
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