BT::PolymorphicCastRegistry Class Reference

Registry for polymorphic shared_ptr cast relationships. More...

#include <polymorphic_cast_registry.hpp>

Public Types
using	CastFunction = std::function< linb::any(const linb::any &)>

Public Member Functions
	PolymorphicCastRegistry (const PolymorphicCastRegistry &)=delete
PolymorphicCastRegistry &	operator= (const PolymorphicCastRegistry &)=delete
	PolymorphicCastRegistry (PolymorphicCastRegistry &&)=delete
PolymorphicCastRegistry &	operator= (PolymorphicCastRegistry &&)=delete
template<typename Derived , typename Base >
void	registerCast ()
	Register a Derived -> Base inheritance relationship.
bool	isConvertible (std::type_index from_type, std::type_index to_type) const
	Check if from_type can be converted to to_type.
bool	canUpcast (std::type_index from_type, std::type_index to_type) const
	Check if from_type can be UPCAST to to_type (not downcast).
nonstd::expected< linb::any, std::string >	tryCast (const linb::any &from, std::type_index from_type, std::type_index to_type) const
	Attempt to cast the value to the target type.
std::set< std::type_index >	getBaseTypes (std::type_index type) const
	Get all registered base types for a given type.
void	clear ()
	Clear all registrations (mainly for testing).

Detailed Description

Registry for polymorphic shared_ptr cast relationships.

This enables passing shared_ptr<Derived> to ports expecting shared_ptr<Base> without breaking ABI compatibility. Users register inheritance relationships at runtime, and the registry handles upcasting/downcasting transparently.

This class is typically owned by BehaviorTreeFactory and passed to Blackboard during tree creation. This avoids global state and makes testing easier.

Usage with BehaviorTreeFactory: BehaviorTreeFactory factory; factory.registerPolymorphicCast<Cat, Animal>(); factory.registerPolymorphicCast<Sphynx, Cat>(); auto tree = factory.createTreeFromText(xml);

Member Function Documentation

canUpcast()

bool BT::PolymorphicCastRegistry::canUpcast ( std::type_index  from_type, std::type_index  to_type  ) const

inline

Check if from_type can be UPCAST to to_type (not downcast).

This is stricter than isConvertible - only allows going from derived to base, not the reverse.

isConvertible()

bool BT::PolymorphicCastRegistry::isConvertible ( std::type_index  from_type, std::type_index  to_type  ) const

inline

Check if from_type can be converted to to_type.

Returns true if:

• from_type == to_type
• from_type is a registered derived type of to_type (upcast)
• to_type is a registered derived type of from_type (downcast)

registerCast()

template<typename Derived , typename Base >

void BT::PolymorphicCastRegistry::registerCast ( )

inline

Register a Derived -> Base inheritance relationship.

This enables:

• Upcasting: shared_ptr<Derived> can be retrieved as shared_ptr<Base>
• Downcasting: shared_ptr<Base> can be retrieved as shared_ptr<Derived> (via dynamic_pointer_cast, may return nullptr if types don't match)

Template Parameters

Derived	The derived class (must inherit from Base)
Base	The base class (must be polymorphic - have virtual functions)

tryCast()

nonstd::expected< linb::any, std::string > BT::PolymorphicCastRegistry::tryCast ( const linb::any &  from, std::type_index  from_type, std::type_index  to_type  ) const

inline

Attempt to cast the value to the target type.

Parameters

from	The source any containing a shared_ptr
from_type	The type_index of the stored type
to_type	The target type_index

Returns

The casted any on success, or an error string on failure

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The documentation for this class was generated from the following file:

• include/behaviortree_cpp/utils/polymorphic_cast_registry.hpp