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修正

2021/05/14 12:32

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スコア16612

answer CHANGED Viewed

@@ -2,6 +2,7 @@
 ```C++
 #include <iostream>
 #include <vector>
+#include <memory>
 class Base {
 public:
@@ -16,17 +17,16 @@
 };
 int main() {
-  std::vector<Base*> vec;
+  std::vector<std::unique_ptr<Base>> vec;
-  vec.push_back(new Base());
+  vec.push_back(std::make_unique<Base>());
-  vec.push_back(new Derived());
+  vec.push_back(std::make_unique<Derived>());
-  vec.push_back(new Base());
+  vec.push_back(std::make_unique<Base>());
-  vec.push_back(new Derived());
+  vec.push_back(std::make_unique<Derived>());
-  for ( Base* item : vec ) {
+  for ( auto& item : vec ) {
-    Derived* der = dynamic_cast<Derived*>(item);
+    Derived* der = dynamic_cast<Derived*>(item.get());
     if ( der ) { der->derived_fn(); }
     else       { item->base_fn(); }
-    delete item;
   }
 }
 ```