C++ Core Guidelines ### Guideline C.21 is “The Rule of Five” ## Simple String ## Simple String - Constructor struct SString { String(char const * cp) : data_(new char[string(cp) + 1]) { string(data_ s{"Pass to a function by value"}; // ... somefn(s); // ... } ## Simple String - Copy Constructor struct SString { // ... String(SString const & rhs) : data_(new char[string(rhs to be moved!"}; // ... somefn(std::move(s)); // ... }; ## Simple String - Move Constructor struct SString { // ... SString(SString && rhs) noexcept : data_(rhs.data_) {

object is created. Data fields of classes should be initialized in the constructor initialization list C. The body of the constructor is available for further operations. ■ Classes can consist of member Access specifier }; class Apple 4 : /*this->*/ mData{i} C Constructor initializer list 5 { D Constructor body 6 } 8 Member functions void Set(int i) { /*this->*/ mData = with override. Never override a non-virtual member function. ■ Prefer class when there is a constructor that checks the invariant, otherwise struct. ## I am Fertig https://AndreasFertig.com ![Imag

move • Both assigned expressions are references - Currently, both lines would call the copy constructor ## So, how can we distinguish between the cases? std::string str2 = str1; // (a) do not move move • Both assigned expressions are references - Before C++11, both lines would call the copy constructor - But they are kind of a different references: The reference at (a) would still be alive after allowed to use move, to move the elements from the old location to the new one, but only if the move constructor of Godzilla is declared as noexcept, to avoid the bad case of “partial work done - there is no

move rather than a copy ## Move Semantics Quick summary ## C++11 introduced move semantics Move constructor and move assignment operator: • Transfer ownership, a.k.a. move from, rather than copy • Used references, T\&\&, only bind to rvalues std::move turns any expression into an rvalue Move constructor / assignment: One rvalue reference parameter Transfer ownership of resources Leave the source (other_condition()) { return local; } return *ptr; } MOVE CONSTRUCTOR MOVE ASSIGNMENT ## Move Constructor / Assignment Similar to copy constructor/assignment, except parameter is an rvalue reference struct

an implementation is allowed to omit the copy/move construction of a class object, even if the constructor selected for the copy/move operation and/or the destructor for the object have side effects. In simply two different ways of referring to the same object. If the first parameter of the selected constructor is an rvalue reference to the object's type, the destruction of that object occurs when the corresponding parameter if the meaning of the program will be unchanged except for the execution of a constructor and destructor for the parameter copy object — when the exception-declaration of a handler ([except

6 }; 7 8 Platformer.prototype = Object.create(Phaser.State.prototype); 9 Platformer.prototype.constructor = Platformer.BootState; 10 11 Platformer.BootState.prototype.init = function (level_file) { 12 8 Platformer.prototype = Object.create(Phaser.State.prototype); 9 Platformer.prototype.constructor = Platformer.LoadingState; 10 11 Platformer.LoadingState.prototype.init = function (level_data) TiledState.prototype = Object.create(Phaser.State.prototype); 9 Platformer.TiledState.prototype.constructor = Platformer.TiledState; 10 11 Platformer.TiledState.prototype.init = function (level_data) { 12

elaborate t so that it has type $ \alpha $ or report an error if it fails. Lean supports anonymous constructor notation, anonymous projections, and various forms of match syntax, including destructuring $ number of constructors, and an associated eliminator (or precursor). Inductive types with one constructor, known as structures, have projections. The full syntax of inductive types is described in Chapter expression and it is an inductive type with one constructor, then one can write $ \langle a_{1}, a_{2}, \ldots, a_{n} \rangle $ to apply the constructor without naming it. For example, $ \langle a, b

Classifier declaration ..... 89 4.1.1 Class declaration ..... 90 Constructor declaration ..... 92 Constructor declaration scopes ..... 94 Nested and inner classifiers ..... 'object' VAL: 'val' VAR: 'var' TYPE_ALIAS: 'typealias' CONSTRUCTOR 'constructor' BY: 'by' COMPANION: 'companion' INIT: 'init' THIS: 'this' program entity. ## I dentifierOrSoftKey Identifier ABSTRACT ANNTOTATION BY CATCH COMPANION CONSTRUCTOR CROSSINLINE DATA DYNAMIC ENUM EXTERNAL FINAL FINALLY IMPORT INFIX INIT INLINE INNER

3.1. Setting bean properties and collaborators ..... 3.3.2. Constructor Argument Resolution ..... 3.3.3. Bean properties and constructor arguments detailed ..... 3.3.4. Method Injection ..... 3 PropertyEditors ..... 33 3.14. Setting a bean property or constructor arg from a property expression ..... 34 3.15. Setting a bean property or constructor arg from a field value ..... 35 3.16. Invoking another if the bean is to be constructed by calling a static factory method instead of using a normal constructor, this will actually be the classname of the factory class. - bean behavioral configuration elements

3.1. Setting bean properties and collaborators ..... 3.3.2. Constructor Argument Resolution ..... 3.3.3. Bean properties and constructor arguments detailed ..... 3.3.4. Method Injection ..... 3 PropertyEditors ..... 33 3.14. Setting a bean property or constructor arg from a property expression ..... 34 3.15. Setting a bean property or constructor arg from a field value ..... 35 3.16. Invoking another if the bean is to be constructed by calling a static factory method instead of using a normal constructor, this will actually be the classname of the factory class. - bean behavioral configuration elements