Conversion Error in C++

Question

I have been coding an assignment in C++ using Binary Search Trees, and while coding my "main" method, came across this error;

 91:37: error: conversion from ‘binaryTree*’ to non-scalar type ‘binaryTree’ requested

Line 91 is as follows;

 binaryTree bt = new binaryTree(root);

and I can't understand what's wrong with it, my lab tutor doesn't understand the error either.

• spelling is definitely correct

Any help would be great - thanks!

Answer 1

The value returned by the operator new has type binaryTree *. So it can be assigned to an object of this type:

binaryTree *bt = new binaryTree(root);

To call a methof for this pointer you have to use operator ->. For example

bt->deleteTree();

Or you should dereference this pointer

( *bt ).deleteTree();

The other way is to use a reference to the allocated object. For example

binaryTree &bt = *new binaryTree(root);

//...

delete &bt;

Or

bt.deleteTree();
delete &bt;

Answer 2

new returns a pointer and bt is not a pointer.

 binaryTree *bt = new binaryTree(root);

Answer 3

You are assigning a pointer(binaryTree*) to a regular variable of type binaryTree. This cannot work.

You should instead do:

binaryTree* bt = new binaryTree(root);