What's the Difference Between C 's 'new' Operator and 'operator new'?

Understanding the Difference Between the "New Operator" and "Operator New" in C

The "new" operator and "operator new" in C perform distinct functions in memory management for creating objects dynamically.

Operator New: Raw Memory Allocation

"Operator new" is a low-level function responsible for allocating raw memory from the operating system. It functions similarly to the "malloc" function, providing a block of memory of a specified size without invoking any constructors or destructors. You can directly invoke "operator new" as follows:

char *x = static_cast<char *>(operator new(100));

Overloading "operator new" allows you to customize memory allocation for specific types or globally. Its signature is typically:

void *operator new(size_t);

The New Operator: Object Creation with Constructors

The "new" operator, in contrast, is typically used to create objects dynamically. It first invokes "operator new" to allocate memory and then initializes the object by invoking the appropriate constructor. This process also involves calling embedded object constructors and base class constructors in the proper order.

For example:

my_class *x = new my_class(0);

Key Distinction

The key distinction between "operator new" and the "new" operator is that the former only allocates raw memory, while the latter combines memory allocation with object creation and initialization. "Operator new" provides more control over memory management, while the "new" operator simplifies object creation by handling both memory allocation and object initialization.

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