How should I call function with template recursively?

c++, recursion, templates

Solution

This is correct:

//in the first case
destroyTree<Data>(element->getLeft());
destroyTree<Data>(element->getRight());

//in the second case
destroyTree<Data>(root);

That is, you have to specify the template argument, as it cannot be deduced by the compiler from the function argument because it is a non-deducible context.

Problem

I'm trying to create a tree class in c++ and i'm not sure how should I use the templates when I am using recursion. for example I have the following function: ``` template <typename Data> void destroyTree(typename AVLTree<Data>::Node* element) { if(!element) { return; } destroyTree(element->getLeft()); destroyTree(element->getRight()); delete element; } ``` or should it be: ``` template <typename Data> void destroyTree(typename AVLTree<Data>::Node* element) { if(!element) { return; } destroyTree<Data>(element->getLeft()); destroyTree<Data>(element->getRight()); delete element; } ``` then if I call it suppose from the following function: ``` template <typename Data> void AVLTree<Data>::function() { destroyTree(root); } ``` or: ``` template <typename Data> void AVLTree<Data>::function() { destroyTree<Data>(root); } ``` I've tried to combine most of the possibilities above but I always get an error. usually it's a `non matching function for call to` If someone has some experience with that issue please help me. Thank you. If I use Nawaz's suggestion I get the following error: Internal Builder is used for build ** g++ -O0 -g3 -Wall -c -fmessage-length=0 -oAVLTest.o ..\AVLTest.cpp g++ -oAVLTree.exe AVLTest.o AVLTest.o: In function ZN15Data_Structures7AVLTreeIiE4Node7getLeftEv': C:/Users/Alex/workspace/AVLTree/Debug/../AVLTree.h:(.text$_ZN15Data_Structures11destroyTreeIiEEvPNS_7AVLTreeIT_E4NodeE[void Data_Structures::destroyTree(Data_Structures::AVLTree::Node*)]+0x47): undefined reference toData_Structures::AVLTree::Node::~Node()' collect2: ld returned 1 exit status Build error occurred, build is stopped Time consumed: 532 ms. what can I do with that? all relevant code is here.

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