art::Handle< T > Class Template Reference

#include <fwd.h>

Classes
class	HandleTag

Public Types
using	element_type = T

Public Member Functions
	~Handle ()=default
constexpr	Handle ()=default
	Handle (GroupQueryResult const &)
	Handle (Handle const &)=default
	Handle (Handle &&)=default
Handle &	operator= (Handle const &)=default
Handle &	operator= (Handle &&)=default
T const &	operator* () const
T const *	operator-> () const
T const *	product () const
	operator bool () const noexcept
bool	isValid () const noexcept
bool	failedToGet () const
Provenance const *	provenance () const
ProductID	id () const
std::shared_ptr< art::Exception const >	whyFailed () const
void	swap (Handle< T > &other)
void	clear ()

Private Attributes
T const *	prod_ {nullptr}
Provenance	prov_ {}
std::shared_ptr< art::Exception const >	whyFailed_ {nullptr}

Detailed Description

template<typename T>
class art::Handle< T >

Definition at line 19 of file fwd.h.

Member Typedef Documentation

template<typename T>

using art::Handle< T >::element_type = T

Definition at line 93 of file Handle.h.

Constructor & Destructor Documentation

template<typename T>

art::Handle< T >::~Handle ( )

default

template<typename T>

constexpr art::Handle< T >::Handle ( )

explicitdefault

template<class T >

art::Handle< T >::Handle ( GroupQueryResult const &  gqr )

explicit

Definition at line 133 of file Handle.h.

  : prod_{nullptr}, prov_{gqr.result()}, whyFailed_{gqr.whyFailed()}
{
  if (gqr.succeeded()) {
    auto const wrapperPtr = dynamic_cast<Wrapper<T> const*>(
      gqr.result()->uniqueProduct(TypeID{typeid(Wrapper<T>)}));
    if (wrapperPtr != nullptr) {
      prod_ = wrapperPtr->product();
    } else {
      Exception e{errors::LogicError};
      e << "Product retrieval via Handle<T> succeeded for product:\n"
        << prov_.productDescription()
        << "but an attempt to interpret it as an object of type '"
        << cet::demangle_symbol(typeid(T).name()) << "' failed.\n";
      whyFailed_ = std::make_shared<art::Exception const>(std::move(e));
    }
  }
}

template<typename T>

art::Handle< T >::Handle ( Handle< T > const &  )

default

template<typename T>

art::Handle< T >::Handle ( Handle< T > &&  )

default

Member Function Documentation

template<class T >

void art::Handle< T >::clear

(

)

Definition at line 236 of file Handle.h.

{
  Handle<T> tmp;
  swap(tmp);
}

template<class T >

bool art::Handle< T >::failedToGet

(

)

const

Definition at line 198 of file Handle.h.

{
  return whyFailed_.get();
}

template<class T >

art::ProductID art::Handle< T >::id ( ) const

inline

Definition at line 212 of file Handle.h.

{
  return prov_.isValid() ? prov_.productID() : ProductID{};
}

template<class T >

bool art::Handle< T >::isValid ( ) const

noexcept

Definition at line 191 of file Handle.h.

{
  return prod_ && prov_.isValid();
}

template<class T >

art::Handle< T >::operator bool ( ) const

inlineexplicitnoexcept

Definition at line 184 of file Handle.h.

{
  return isValid();
}

template<class T >

T const & art::Handle< T >::operator* ( ) const

inline

Definition at line 156 of file Handle.h.

{
  return *product();
}

template<class T >

T const * art::Handle< T >::operator-> ( ) const

inline

Definition at line 175 of file Handle.h.

{
  return product();
}

template<typename T>

Handle& art::Handle< T >::operator= ( Handle< T > const &  )

default

template<typename T>

Handle& art::Handle< T >::operator= ( Handle< T > &&  )

default

template<class T >

T const * art::Handle< T >::product

(

)

const

Definition at line 163 of file Handle.h.

{
  if (failedToGet()) {
    throw *whyFailed_;
  }
  if (prod_ == nullptr)
    throw Exception(art::errors::NullPointerError)
      << "Attempt to de-reference product that points to 'nullptr'.\n";
  return prod_;
}

template<class T >

art::Provenance const * art::Handle< T >::provenance ( ) const

inline

Definition at line 205 of file Handle.h.

{
  return &prov_;
}

template<class T>

void art::Handle< T >::swap

(

Handle< T > &

other

)

Definition at line 229 of file Handle.h.

{
  std::swap(*this, other);
}

template<class T >

std::shared_ptr< art::Exception const > art::Handle< T >::whyFailed ( ) const

inline

Definition at line 219 of file Handle.h.

{
  return whyFailed_;
}

Member Data Documentation

template<typename T>

T const* art::Handle< T >::prod_ {nullptr}

private

Definition at line 124 of file Handle.h.

template<typename T>

Provenance art::Handle< T >::prov_ {}

private

Definition at line 125 of file Handle.h.

template<typename T>

std::shared_ptr<art::Exception const> art::Handle< T >::whyFailed_ {nullptr}

private

Definition at line 126 of file Handle.h.

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

• art/art/Framework/Principal/fwd.h
• art/art/Framework/Principal/Handle.h