pointer = new type;
  pointer = new type( initializer );
  pointer = new type[size];
  pointer = new( arg-list ) type...

The new operator (valid only in C++) allocates a new chunk of memory to hold a variable of type type and returns a pointer to that memory. An optional initializer can be used to initialize the memory. Allocating arrays can be accomplished by providing a size parameter in brackets.

The optional arg-list parameter can be used with any of the other formats to pass a variable number of arguments to an overloaded version of new(). For example, the following code shows how the new() function can be overloaded for a class and then passed arbitrary arguments:

  class Base {
  public:
    Base() { }

    void *operator new( unsigned int size, string str ) {
      cout << "Logging an allocation of " << size << " bytes for new object '" << str << "'" << endl;
      return malloc( size );
    }

    int var;
    double var2;
  };

  ...

  Base* b = new ("Base instance 1") Base;

If an int is 4 bytes and a double is 8 bytes, the above code generates the following output when run:

  Logging an allocation of 12 bytes for new object 'Base instance 1'