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Qore Programming Language - C/C++ Library 2.0.0
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helper class to manage variable references passed to functions and class methods, stack only, cannot be dynamically allocated More...
#include <QoreTypeSafeReferenceHelper.h>
Public Member Functions | |
DLLEXPORT | QoreTypeSafeReferenceHelper (const ReferenceNode *ref, ExceptionSink *xsink) |
initializes the object and tries to get the pointer to the pointer of the lvalue expression target | |
DLLEXPORT | QoreTypeSafeReferenceHelper (ExceptionSink *xsink) |
Initializes the object without a reference. | |
DLLEXPORT | ~QoreTypeSafeReferenceHelper () |
destroys the object | |
DLLEXPORT int | assign (QoreValue val) |
assigns a value to the reference, assumes the reference is valid | |
DLLEXPORT void | close () |
Closes the object and unlocks all locks. | |
DLLEXPORT ExceptionSink * | getExceptionSink () const |
Returns the ExceptionSink object. | |
DLLEXPORT const QoreTypeInfo * | getReferenceTypeInfo () const |
Returns the type of the reference. | |
DLLEXPORT qore_type_t | getType () const |
returns the type of the reference's value | |
DLLEXPORT const char * | getTypeName () const |
returns the type name of the reference's value | |
DLLEXPORT AbstractQoreNode * | getUnique () |
returns a pointer to the value with a unique reference count (so it can be updated in place) | |
template<typename T > | |
DLLLOCAL T * | getUnique () |
returns a pointer to the value with a unique reference count (so it can be updated in place) | |
DLLEXPORT const QoreValue | getValue () const |
returns the reference's value | |
DLLEXPORT AutoVLock & | getVLock () const |
Returns the variable lock. | |
DLLEXPORT bool | isLocked () const |
Returns true if managing a lock. | |
DLLEXPORT int | moveToHashObjKey (const char *key, bool for_remove=false) |
Moves the reference to the given key of the hash or object of the current value. | |
DLLEXPORT | operator bool () const |
returns true if the reference is valid, false if not | |
DLLEXPORT QoreValue | removeHashObjKey (const char *key) |
Removes the given key of the current hash or object. | |
DLLEXPORT int | reset (const ReferenceNode *ref, ExceptionSink *xsink) |
Clears any existing reference and assigns the reference to use. | |
DLLEXPORT int | set (const ReferenceNode *ref) |
Assigns the reference to use. | |
DLLEXPORT int | setObjKey (QoreObject *obj, const char *key, bool for_remove=false) |
Moves the reference to the given key of the given object. | |
helper class to manage variable references passed to functions and class methods, stack only, cannot be dynamically allocated
Takes care of safely accessing ReferenceNode objects, for example when they are passed as arguments to a builtin function or method. Locks are automatically acquired in the constructor if necessary and released in the destructor. The constructor could raise a Qore-language exception if there is a deadlock acquiring any locks to access the ReferenceNode's value as given by the lvalue expression, so the object should be checked for this state right after the constructor as in the following example:
DLLEXPORT QoreTypeSafeReferenceHelper::QoreTypeSafeReferenceHelper | ( | ExceptionSink * | xsink | ) |
Initializes the object without a reference.
After this, use set(const ReferenceNode* ref)
DLLEXPORT QoreTypeSafeReferenceHelper::QoreTypeSafeReferenceHelper | ( | const ReferenceNode * | ref, |
ExceptionSink * | xsink ) |
initializes the object and tries to get the pointer to the pointer of the lvalue expression target
ref | the ReferenceNode to use |
xsink | Qore-language exceptions raised will be added here (for example, a deadlock accessing the object) |
DLLEXPORT int QoreTypeSafeReferenceHelper::assign | ( | QoreValue | val | ) |
assigns a value to the reference, assumes the reference is valid
val | the value to assign (must be already referenced for the assignment) |
DLLEXPORT void QoreTypeSafeReferenceHelper::close | ( | ) |
Closes the object and unlocks all locks.
After this call, the object cannot be used
DLLEXPORT qore_type_t QoreTypeSafeReferenceHelper::getType | ( | ) | const |
returns the type of the reference's value
DLLEXPORT const char * QoreTypeSafeReferenceHelper::getTypeName | ( | ) | const |
returns the type name of the reference's value
DLLEXPORT AbstractQoreNode * QoreTypeSafeReferenceHelper::getUnique | ( | ) |
returns a pointer to the value with a unique reference count (so it can be updated in place)
assumes the reference is valid and the lvalue holds a reference-counted AbstractQoreNode*, if not, this call will cause a segfault
Referenced by getUnique().
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inline |
returns a pointer to the value with a unique reference count (so it can be updated in place)
assumes the reference is valid and the lvalue holds a reference-counted AbstractQoreNode*, if not, this call will cause a segfault
References getUnique().
DLLEXPORT const QoreValue QoreTypeSafeReferenceHelper::getValue | ( | ) | const |
returns the reference's value
DLLEXPORT QoreTypeSafeReferenceHelper::operator bool | ( | ) | const |
returns true if the reference is valid, false if not
false will only be returned if a Qore-language exception was raised in the constructor
DLLEXPORT int QoreTypeSafeReferenceHelper::reset | ( | const ReferenceNode * | ref, |
ExceptionSink * | xsink ) |
Clears any existing reference and assigns the reference to use.
DLLEXPORT int QoreTypeSafeReferenceHelper::set | ( | const ReferenceNode * | ref | ) |
Assigns the reference to use.
Only to be used after QoreTypeSafeReferenceHelper(ExceptionSink* xsink)