u01: Add stream output to node

u01/main.cpp

@@ -1,7 +1,10 @@
+#include <iostream>
+
 #include "node.h"
 
 int main(int argc, char **argv) {
   node *t = create_complete_tree(2, 4);
+  std::cout << *t;
   delete t;
   t = nullptr;
   node *root = new node("root");

u01/node.cpp

@@ -32,6 +32,18 @@ node *node::get_child(std::size_t i) const { return children[i]; }
 
 void node::add_child(node *child) { children.push_back(child); }
 
+void node::print(std::ostream &str, std::size_t depth) const {
+  str << std::string(depth, '\t') << get_name() << std::endl;
+  for (node *child : children) {
+    child->print(str, depth + 1);
+  }
+}
+
+std::ostream &operator<<(std::ostream &os, node &n) {
+  n.print(os);
+  return os;
+}
+
 node *create_complete_tree(std::size_t nr_child_nodes,
                            unsigned int tree_depth) {
   node *n = new node();

u01/node.h

@@ -13,6 +13,7 @@ public:
   unsigned int get_nr_children() const;
   node *get_child(std::size_t i) const;
   void add_child(node *child);
+  void print(std::ostream &str, std::size_t depth = 0) const;
 
 private:
   std::string name;
@@ -20,4 +21,6 @@ private:
   static unsigned int node_id;
 };
 
+extern std::ostream &operator<<(std::ostream &os, node &n);
+
 node *create_complete_tree(std::size_t nr_child_nodes, unsigned int tree_depth);

u01/tests.cpp

@@ -1,5 +1,6 @@
 #include <catch2/catch_test_macros.hpp>
 #include <iostream>
+#include <sstream>
 
 #include "node.h"
 
@@ -111,3 +112,41 @@ TEST_CASE("Create complete tree") {
 
   delete t;
 }
+
+TEST_CASE("Print complete tree") {
+  const std::size_t nr_child_nodes = 2;
+  const unsigned int tree_depth = 4;
+  node *t = create_complete_tree(nr_child_nodes, tree_depth);
+
+  int count = get_node_id(t);
+
+  std::stringstream output;
+  t->print(output);
+
+  std::stringstream expected;
+  expected << "node_" << count++ << std::endl;
+  for (size_t i = 0; i < 2; i++) {
+    expected << "\tnode_" << count++ << std::endl;
+    for (size_t j = 0; j < 2; j++) {
+      expected << "\t\tnode_" << count++ << std::endl;
+      for (size_t k = 0; k < 2; k++) {
+        expected << "\t\t\tnode_" << count++ << std::endl;
+      }
+    }
+  }
+  REQUIRE(output.str() == expected.str());
+
+  delete t;
+}
+
+TEST_CASE("Print stream overload") {
+  node n("foo");
+
+  std::stringstream output1;
+  n.print(output1);
+
+  std::stringstream output2;
+  output2 << n;
+
+  REQUIRE(output1.str() == output2.str());
+}