C++ New Library - operator delete

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Description

It deallocates storage space.

Declaration

Following is the declaration for operator new[].

	
void operator delete (void* ptr) throw();	(ordinary delete)
void operator delete (void* ptr, const std::nothrow_t& nothrow_constant) throw();	    (nothrow delete)
void operator delete (void* ptr, void* voidptr2) throw();             (placement delete)

C++11

		
void operator delete (void* ptr) noexcept;   (ordinary delete)
void operator delete (void* ptr, const std::nothrow_t& nothrow_constant) noexcept;	    (nothrow delete)
void operator delete (void* ptr, void* voidptr2) noexcept;      (placement delete)

C++14

		
void operator delete (void* ptr) noexcept;                    (ordinary delete)
void operator delete (void* ptr, const std::nothrow_t& nothrow_constant) noexcept;             (nothrow delete)
void operator delete (void* ptr, void* voidptr2) noexcept;                (placement delete)
void operator delete (void* ptr, std::size_t size) noexcept;	            (ordinary delete with size)
void operator delete (void* ptr, std::size_t size,
                      const std::nothrow_t& nothrow_constant) noexcept;            (ordinary delete with size)

Parameters

• size − It contain size in bytes of the requested memory block.

• nothrow_value − It contains the constant nothrow.

• ptr − It is a pointer to an already-allocated memory block of the proper size.

• voidptr2 − It is a void pointer.

Return Value

none

Exceptions

No-throw guarantee − this function never throws exceptions.

Data races

It modifies the storage referenced by the returned value.

Example

In below example explains about new operator.

#include <iostream>

struct MyClass {
   MyClass() {std::cout <<"It is a MyClass() constructed\n";}
   ~MyClass() {std::cout <<"It is a MyClass() destroyed\n";}
};

int main () {
   MyClass * pt = new (std::nothrow) MyClass;
   delete pt;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

It is a MyClass() constructed
It is a MyClass() destroyed