c++ - When do casts call the constructor of the new type?

Question

What are the rules to determine whether or not a particular static_cast will call a class's constructor? How about c style/functional style casts?

Answer 1

A constructor for a class type is called whenever a new instance of that type is created. If a cast creates a new object of that class type then a constructor is called. Overload resolution determines which of the constructors for a class type are called given particular arguments.

If the target type of a static_cast is a class type, it will create a new object of the target type.

A const_cast, dynamic_cast, or reinterpret_cast will never create a new class-type object, and thus will never call a constructor.

Since a C-style cast always performs some combination of static_cast, const_cast, and reinterpret_cast, it will create a new object in the same circumstances that a static_cast would create a new object.