document equality comparability of Iterator (necessary for Iterator of Iterators)

bkietz · bkietz · commit 927ae0f6b8ea · 2019-10-16T09:49:20.000-04:00
diff --git a/cpp/src/arrow/util/iterator.h b/cpp/src/arrow/util/iterator.h
@@ -89,7 +89,9 @@ class Iterator : public util::EqualityComparable<Iterator<T>> {
     return status;
   }
 
-  /// Iterators will only compare equal if they are both null
+  /// Iterators will only compare equal if they are both null.
+  /// Equality comparability is required to make an Iterator of Iterators
+  /// (to check for the end condition).
   bool Equals(const Iterator& other) const { return ptr_ == other.ptr_; }
 
   explicit operator bool() const { return ptr_ != NULLPTR; }

Original file line number	Diff line number	Diff line change
`@@ -89,7 +89,9 @@ class Iterator : public util::EqualityComparable<Iterator<T>> {`
`89`	`89`	`return status;`
`90`	`90`	`}`
`91`	`91`
`92`		`- /// Iterators will only compare equal if they are both null`
	`92`	`+ /// Iterators will only compare equal if they are both null.`
	`93`	`+ /// Equality comparability is required to make an Iterator of Iterators`
	`94`	`+ /// (to check for the end condition).`
`93`	`95`	`bool Equals(const Iterator& other) const { return ptr_ == other.ptr_; }`
`94`	`96`
`95`	`97`	`explicit operator bool() const { return ptr_ != NULLPTR; }`