Add Cv4.

README.md

@@ -26,6 +26,7 @@ Deadliny:
 | 30.09.2021 | Úvod, nároky, syntaxe, I/O | [CV1](https://gitlab.mff.cuni.cz/teaching/nprg041/Smelko/cpp-cvika/-/blob/master/prezentacie/Cv1.pdf) |
 | 07.10.2021 | Stringy, znaky, streamy | [CV2](https://gitlab.mff.cuni.cz/teaching/nprg041/Smelko/cpp-cvika/-/blob/master/prezentacie/Cv2.pdf) |
 | 14.10.2021 | Hlavičky, třídy, objekty | [CV3](https://gitlab.mff.cuni.cz/teaching/nprg041/Smelko/cpp-cvika/-/blob/master/prezentacie/Cv3.pdf) |
+| 21.10.2021 | Kontejnery, iterátory | [CV4](https://gitlab.mff.cuni.cz/teaching/nprg041/Smelko/cpp-cvika/-/blob/master/prezentacie/Cv4.pdf) |
 
 
 ## Úkoly:

vzorove-priklady/implicit_constructors.cpp

+#include <vector>
+#include <string>
+#include <memory>
+
+struct CopyableStructure
+{
+    std::vector<std::string> data;
+};
+
+struct NotCopyableStructure
+{
+    std::unique_ptr<int> data;
+};
+
+int main()
+{
+    {
+        CopyableStructure original;
+        CopyableStructure copy(original);
+    }
+    
+    {
+        NotCopyableStructure original;
+        // does not compile because std::unique_ptr does not have copy constructor
+        // so copy constructor of NotCopyableStructure is not implicitly generated
+        NotCopyableStructure copy(original); 
+    }
+
+    return 0;
+}
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vzorove-priklady/iterators.cpp

+#include <vector>
+#include <string>
+#include <iostream>
+
+struct person
+{
+    std::string name;
+    int age;
+};
+
+class person_catalog
+{
+    std::vector<person> persons_;
+public:
+    person_catalog(std::vector<person> persons)
+        : persons_(std::move(persons)) {}
+
+
+    struct iterator
+    {
+        person_catalog& owner;
+        int current_index;
+        
+        iterator(person_catalog& owner, int starting_index)
+            : owner(owner), current_index(starting_index) {}
+
+        person& operator*() 
+        {
+            return owner.persons_[current_index];
+        }
+
+        person* operator->()
+        {
+            return &owner.persons_[current_index];
+        }
+
+        bool operator!=(const iterator& oth) const
+        {
+            return &owner != &oth.owner || current_index != oth.current_index;
+        }
+
+        iterator& operator++()
+        {
+            current_index++;
+            return *this;
+        }
+    };
+
+    iterator begin()
+    {
+        return iterator(*this, 0);
+    }
+
+    iterator end()
+    {
+        return iterator(*this, persons_.size());
+    }
+};
+
+int main()
+{
+    std::vector<person> persons;
+    persons.push_back(person{"Adam", 24});
+    persons.push_back(person{"Eva", 18});
+    persons.push_back(person{"Michal", 13});
+
+    person_catalog catalog(persons);
+
+    for (auto it = catalog.begin(); it != catalog.end(); ++it)
+    {
+        std::cout << it->name << " ";
+    }
+
+    std::cout << std::endl;
+
+    for (auto person : catalog)
+        std::cout << person.name << " ";
+
+    std::cout << std::endl;
+}
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