What is the difference between copy list initialization and direct list initialization?

Why does the standard differentiate between direct-list-initialization and copy-list-initialization? We know that T v(x); is called direct-initialization, while T v = x; is called copy-initialization, meaning that it will construct a temporary T from x that will get copied / moved into v (which is most likely elided).

What is direct initialization in C++?

Direct initialization applies when initializing objects without explicit assignment. It also is also used for explicit casts, whether function-style or via static_cast and applies to Lambda closure arguments captured by value (which may be regarded as a special case of member initialization).

Does copy initialization call copy constructor?

In other words, a good compiler will not create a copy for copy-initialization when it can be avoided; instead it will just call the constructor directly — ie, just like for direct-initialization.

How do you initialize a list in C++?

Initializer List is used in initializing the data members of a class. The list of members to be initialized is indicated with constructor as a comma-separated list followed by a colon. Following is an example that uses the initializer list to initialize x and y of Point class.

What is the difference between initialization and assignment in C++?

What is the difference between initialization and assignment? Initialization gives a variable an initial value at the point when it is created. Assignment gives a variable a value at some point after the variable is created.

What is meant by copy initialization?

Copy initialization is used when a new object is created with some existing object. This is used when we want to assign existing object to new object. Both the objects uses separate memory locations.

What is meant by direct initialization of an array give an example?

When we directly provide the elements of an array during its initialization/declaration is called direct initialization of an Array in Java. For Example – int[ ] numbers = {1, 2, 3, 4, 5}; klondikegj and 4 more users found this answer helpful.

What is direct initialization?

Direct Initialization or Assignment Operator (Syntax) This assigns the value of one object to another object both of which are already exists. Copy initialization is used when a new object is created with some existing object. This is used when we want to assign existing object to new object.

Why initialization list is used in C++?

The initializer list is used to directly initialize data members of a class. An initializer list starts after the constructor name and its parameters.

What is the difference between list and vector in C++?

Both vector and list are sequential containers of C++ Standard Template Library. List stores elements at non contiguous memory location i.e. it internally uses a doubly linked list i.e. Advertisements. Whereas, vector stores elements at contiguous memory locations like an array i.e.

What is the different between assigning and initializing give examples?

Is there a difference between copy initialization and direct initialization in C++?

Is there a difference between copy initialization and direct initialization in C++? The Copy initialization can be done using the concept of copy constructor. As we know that the constructors are used to initialize the objects.

How to initialize a copy of an object?

The Copy initialization can be done using the concept of copy constructor. As we know that the constructors are used to initialize the objects. We can create our copy constructor to make a copy of some other object, or in other words, initialize current object with the value of another object.

What happens when you move an initializer to another object?

In principle, a copy of the initializer (the object we are copying from) is placed into the initialized object. However, such a copy may be optimized away (elided), and a move operation (based on move semantics) may be used if the initializer is an rvalue.

Why does direct initialization of a constructor require a conversion?

There is no conversion, much less a user defined conversion, needed to call that constructor (note that no const qualification conversion happens here either). And so direct initialization will call it. As said above, copy initialization will construct a conversion sequence when a has not type B or derived from it (which is clearly the case here).