Handle a type parameter u For a built-in and simple data type, there's almost no difference between by-value and by-reference in efficiency a For a class or complex data type, by-reference is usually used for efficiency But for type parameters of a template, we won't know in advance the real type it represents It is recommended declared them as const reference for the worst situation template typename elemtype> Binary Tree<elemtype>: find( const elemtype& value)Handle a type parameter ◼ For a built-in and simple data type, there’s almost no difference between by-value and by-reference in efficiency ◼ For a class or complex data type, by-reference is usually used for efficiency ◼ But for type parameters of a template, we won’t know in advance the real type it represents ◼ It is recommended declared them as const reference for the worst situation template < typename elemtype > BinaryTree<elemtype>::find(const elemtype& value) {};