donner::svg::RecursionGuard Struct Reference

Helper to guard against recursion when evaluating references. More...

#include "donner/svg/graph/RecursionGuard.h"

Public Member Functions
	RecursionGuard ()=default
	efault constructor.
bool	hasRecursion (Entity entity) const
	Returns true if this entity has been seen before, indicating a cycle has been detected.
void	add (Entity entity)
	Add the given entity to the set of entities that have been seen.
RecursionGuard	with (Entity entity) const
	Create a new RecursionGuard with the given entity added to the set of entities that have been seen.

Detailed Description

Helper to guard against recursion when evaluating references.

This is used to prevent infinite recursion when reference hierarchies contain cycles.

Usage:

RecursionGuard guard;
Entity current = ...;
while (current) {
  Entity target = getTarget(current);
  if (guard.hasRecursion(target)) {
    break;
  }
 
  guard.add(target);
  current = target;
}

There is also a shorthand when passing a RecursionGuard as a parameter:

void doSomething(Entity element, RecursionGuard guard) {
  Entity next = getNext(current);
  if (next != entt::null) {
    doSomething(next, guard.with(next));
  }
}

Member Function Documentation

add()

void donner::svg::RecursionGuard::add ( Entity entity )

inline

Add the given entity to the set of entities that have been seen.

Parameters

entity

Entity to add.

hasRecursion()

bool donner::svg::RecursionGuard::hasRecursion ( Entity entity ) const

inline

Returns true if this entity has been seen before, indicating a cycle has been detected.

Parameters

entity

Entity to check.

with()

RecursionGuard donner::svg::RecursionGuard::with ( Entity entity ) const

inline

Create a new RecursionGuard with the given entity added to the set of entities that have been seen.

Parameters

entity

Entity to add.

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

• donner/svg/graph/RecursionGuard.h