{{fbdoc item="title" value="New and Delete"}}----
The different operators **New** (//Implicit///Overload/Expression/Placement) and **Delete** (//Implicit///Overload/Statement), and all their array-versions **New[]** and **Delete[]**

{{fbdoc item="section" value="Definition"}}
	There may be confusion in the user mind between the different operators **New** and **Delete** (despite the documentation that distinguishes them from each other through some different pages):
		- ##//'Operator New Implicit' (inaccessible by user)//##:
				**""-""** It is a static function that only allocates memory (it is not very different from ##[[KeyPgAllocate|Allocate]]##).
		- ##[[KeyPgOpNewOverload|Operator New Overload]]##:
				**""-""** It is a member operator (static function) that can overload the ##//'Operator New Implicit'//## only for user-defined types.
				**""-""** So the user can define its own dynamic memory allocation process part (the following process part for implicit data construction can not be modified).
		- ##//'Operator Delete Implicit' (inaccessible by user)//##:
				**""-""** It is a static sub that only frees the memory (it is not very different from ##[[KeyPgDeallocate|Deallocate]]##).
		- ##[[KeyPgOpDeleteOverload|Operator Delete Overload]]##:
				**""-""** It is a member operator (static sub) that can overload the ##//'Operator Delete Implicit'//## only for user-defined types.
				**""-""** So the user can define its own memory deallocation process part (the previous process part for implicit data destruction can not be modified).
		- ##[[KeyPgOpNew|Operator New Expression]]##:
				**""-""** It starts by using the ##'Operator New //Implicit///Overload'## (the implicit, or the overload if exists) to allocate memory.
				**""-""** Then it invokes the constructor for the right type of object. If that object contains any other objects (either embedded or as base types) those constructors as invoked as well.
				**""-""** So the final result is memory allocated and object constructed.
				**""-""** This operator applies to pre-defined types (except fixed-length strings) as well as user-defined types.
		- ##[[KeyPgOpDelete|Operator Delete Statement]]##:
				**""-""** It starts by invoking the destructor for the right type of object. If that object contains any other objects (either embedded or as base types) those destructors as invoked as well.
				**""-""** Then it uses the ##'Operator Delete //Implicit///Overload'## (the implicit, or the overload if exists) to deallocate memory.
				**""-""** So the final result is object destroyed and memory freed.
				**""-""** This operator applies to pre-defined types (except fixed-length strings) as well as user-defined types.
		- ##[[KeyPgOpPlacementNew|Operator Placement New]]##:
				**""-""** It only constructs object at a specified memory address (already allocated). This operator applies to pre-defined types (except fixed-length strings) as well as user-defined types.

			
	Similar definition for ##'Operator New[] //Implicit///Overload/Expression'##, ##'Operator Delete[] //Implicit///Overload/Statement'## and ##'Operator Placement New[]'##, which are only the (one-dimensional) array-versions of the previous operators (there is construction/destruction loop on the array elements).
	
	Instances created with ##'Operator New Overload/Expression'## must be freed with ##'Operator Delete Overload/Statement'##.
	Instance array created with ##'Operator New[] Overload/Expression'## must be freed with ##'Operator Delete[] Overload/Statement'##, the array-version of ##'Operator Delete Overload/Statement'##.
	User can not mix and match the different versions of the operators.
	
	Instances constructed at a specified memory address with ##'Operator Placement New'## must never induce a symmetric freeing with any ##'Operator Delete'## on the address (because the memory has been allocated in another way than by the ##'Operator Placement New'##).
	Instance array constructed at a specified memory address with ##'Operator Placement New[]'## must never induce a symmetric freeing with any ##'Operator Delete[]'## on the address (because the memory has been allocated in another way than by the ##'Operator Placement New[]'##).
	For such UDT instances, the proper way to just destroy each instance if necessary, is to call only the destructor if one exists (implicitly or explicitly), with syntax as for a member method by using member access operator.
	
	**Note:** Any operators //'New[]'// or //'Delete[]'// (the array versions for  statement/expression/overload operators) and even the overload operator //'Delete'// are not directly compatible with inheritance polymorphism (sub-type polymorphism), because the use of a sub-type pointer (instead of the real type) mainly fails for accessing the other elements (except the first).

{{fbdoc item="section" value="Algorithm (applied to user-defined types)"}}
	Operator New/New[] Expression:
		%%
'       OPERATOR NEW/NEW[] EXPRESSION
'                     V
'                     |
'              call if there is >----------------------------.
'                   else                                     :
'                     v                                      v
'       (Operator New/New[] Implicit)          (Operator New/New[] Overload)
'                     :                                      :
'          BASIC MEMORY ALLOCATION            USER BODY for memory allocation
'                     :                                      :
'                     :<-------------------------------------'
'                     |
'                     |<-------------------------------------.
'                     |                                      :
'        DATA FIELDS INITIALIZATION                          :
'        OBJECT FIELDS CONSTRUCTION                          :
'           (VPTR INITIALIZATION)                            :
'                     |                                      :
'              call if there is >-----------.                :
'                   else                    :                :
'                     v                     v                :
'                     :            (User Constructor)        :
'                     :                     :                :
'                     :                 USER BODY            :
'                     :                     :                :
'                     :<--------------------'                :
'                     |                                      :
'        loop if array-version NEW[] >-----------------------'
'                   else
'                     v
'                     |
'                     V
%%

	Operator Delete/Delete[] Statement:
		%%
'     OPERATOR DELETE/DELETE[] STATEMENT
'                     V
'                     |
'                     |<-------------------------------------.
'                     |                                      :
'          (VPTR REINITIALIZATION)                           :
'                     |                                      :
'              call if there is >-----------.                :
'                   else                    :                :
'                     v                     v                :
'                     :             (User Destructor)        :
'                     :                     :                :
'                     :                 USER BODY            :
'                     :                     :                :
'                     :<--------------------'                :
'                     |                                      :
'         OBJECT FIELDS DESTRUCTION                          :
'                     |                                      :
'       loop if array-version DELETE[] >---------------------'
'                   else
'                     v
'                     |
'              call if there is >----------------------------.
'                   else                                     :
'                     v                                      v
'    (Operator Delete/Delete[] Implicit)    (Operator Delete/Delete[] Overload)
'                     :                                      :
'         BASIC MEMORY DEALLOCATION          USER BODY for memory deallocation
'                     :                                      :
'                     :<-------------------------------------'
'                     |
'                     V
%%

	Operator Placement New/New[]:
		%%
'        OPERATOR PLACEMENT NEW/NEW[]
'                     V
'                     |
'                     |<-------------------------------------.
'                     |                                      :
'        DATA FIELDS INITIALIZATION                          :
'        OBJECT FIELDS CONSTRUCTION                          :
'           (VPTR INITIALIZATION)                            :
'                     |                                      :
'              call if there is >-----------.                :
'                   else                    :                :
'                     v                     v                :
'                     :             (User Constructor)       :
'                     :                     :                :
'                     :                 USER BODY            :
'                     :                     :                :
'                     :<--------------------'                :
'                     |                                      :
'        loop if array-version NEW[] >-----------------------'
'                   else
'                     v
'                     |
'                     V
%%
{{fbdoc item="section" value="Example"}}
	Example that uses the operators New (Overload/Expression/Placement) and Delete (Overload/Statement), and all their array-versions New[] and Delete[]:
	(all the 10 operators New and Delete accessible by the user):
		{{fbdoc item="filename" value="examples/manual/proguide/newdelete/operators.bas"}}%%(freebasic)
Declare Sub printArray (Byref label As String = "", array() As String)


Type UDT
	Declare Constructor ()
	Declare Destructor ()
	Declare Operator New (Byval size As Uinteger) As Any Ptr    ' Operator New Overload
	Declare Operator New[] (Byval size As Uinteger) As Any Ptr  ' Operator New[] Overload
	Declare Operator Delete (Byval buf As Any Ptr)              ' Operator Delete Overload
	Declare Operator Delete[] (Byval buf As Any Ptr)            ' Operator Delete[] Overload
	Dim As String array (1 To 4)
End Type

Constructor UDT ()
	Static As Integer n
	Print "    Constructor"
	printArray("        init: @" & @This & " (descriptors) -> ", This.array())
	For i As Integer = Lbound(This.array) To Ubound(This.array)
		This.array(i) = Chr(Asc("a") + n + i - Lbound(This.array))
	Next i
	printArray(" => ", This.array())
	Print
	n += Ubound(This.array)- Lbound(This.array) + 1
End Constructor

Destructor UDT ()
	Print "    Destructor"
	printArray("        erase: @" & @This & " (descriptors) -> ", This.array())
	Erase This.array
	printArray(" => ", This.array())
	Print
End Destructor

Operator UDT.New (Byval size As Uinteger) As Any Ptr
	Print "    Operator New Overload"
	Dim As Any Ptr p = Allocate(size)                   ' Memory allocation (with passed size)
	Print "        memory allocation: ";
	Print size & " Bytes from @" & p
	Return p                                            ' Returning memory pointer
End Operator

Operator UDT.New[] (Byval size As Uinteger) As Any Ptr
	Print "    Operator New[] Overload"
	Dim As Any Ptr p = Allocate(size)                   ' Memory allocation (with passed size)
	Print "        memory allocation: ";
	Print size & " Bytes from @" & p
	Return p                                            ' Returning memory pointer
End Operator

Operator UDT.Delete (Byval buf As Any Ptr)
	Print "    Operator Delete Overload"
	Deallocate(buf)                                     ' Memory deallocation (with passed pointer)
	Print "        memory deallocation: ";
	Print "for @" & buf
End Operator

Operator UDT.Delete[] (Byval buf As Any Ptr)
	Print "    Operator Delete[] Overload"
	Deallocate(buf)                                     ' Memory deallocation (with passed pointer)
	Print "        memory deallocation: ";
	Print "for @" & buf
End Operator


Print "Operator New Expression"
Dim As UDT Ptr pu1 = New UDT         ' Operator New Expression
Print "Operator Delete Statement"
Delete pu1                           ' Operator Delete Statement
Sleep

Print
Print "Operator New[] Expression"      
Dim As UDT Ptr pu2 = New UDT[2]      ' Operator New[] Expression
Print "Operator Delete[] Statement"
Delete[] pu2                         ' Operator Delete[] Statement
Sleep

Dim As Byte buffer(1 To 256)
Dim As Any Ptr p = @buffer(1)

Print
Print "Operator Placement New"
Dim As UDT Ptr pu3 = New(p) UDT      ' Operator Placement New
Print "User call of Destructor"
pu3->Destructor()                    ' User Call of Destructor
Sleep

Print
Print "Operator Placement New[]"
Dim As UDT Ptr pu4 = New(p) UDT[2]   ' Operator Placement New[]
For i As Integer = 0 To 1
	Print "User Call of Destructor"
	pu4[i].Destructor()              ' User Call of Destructor
Next i
Sleep


Sub printArray (Byref label As String = "", array() As String)
	Print label & "{";
	For i As Integer = Lbound(array) To Ubound(array)
		Print """" & array(i) & """";
		If i < Ubound(array) Then
			Print ",";
		End If
	Next I
	Print "}";
End Sub
%%Output example (for a 64-bit system):
			%%
Operator New Expression
	Operator New Overload
		memory allocation: 96 Bytes from @1728352
	Constructor
		init: @1728352 (descriptors) -> {"","","",""} => {"a","b","c","d"}
Operator Delete Statement
	Destructor
		erase: @1728352 (descriptors) -> {"a","b","c","d"} => {"","","",""}
	Operator Delete Overload
		memory deallocation: for @1728352
%%
			%%
Operator New[] Expression
	Operator New[] Overload
		memory allocation: 200 Bytes from @1728352
	Constructor
		init: @1728360 (descriptors) -> {"","","",""} => {"e","f","g","h"}
	Constructor
		init: @1728456 (descriptors) -> {"","","",""} => {"i","j","k","l"}
Operator Delete[] Statement
	Destructor
		erase: @1728456 (descriptors) -> {"i","j","k","l"} => {"","","",""}
	Destructor
		erase: @1728360 (descriptors) -> {"e","f","g","h"} => {"","","",""}
	Operator Delete[] Overload
		memory deallocation: for @1728352
%%
			%%
Operator Placement New
	Constructor
		init: @1375248 (descriptors) -> {"","","",""} => {"m","n","o","p"}
User call of Destructor
	Destructor
		erase: @1375248 (descriptors) -> {"m","n","o","p"} => {"","","",""}
%%
			%%
Operator Placement New[]
	Constructor
		init: @1375248 (descriptors) -> {"","","",""} => {"q","r","s","t"}
	Constructor
		init: @1375344 (descriptors) -> {"","","",""} => {"u","v","w","x"}
User Call of Destructor
	Destructor
		erase: @1375248 (descriptors) -> {"q","r","s","t"} => {"","","",""}
User Call of Destructor
	Destructor
		erase: @1375344 (descriptors) -> {"u","v","w","x"} => {"","","",""}
%%
{{fbdoc item="section" value="See also"}}
	- [[KeyPgOperator|Operator]]
	- [[KeyPgConstructor|Constructor]]
	- [[KeyPgDestructor|Destructor]]

{{fbdoc item="back" value="CatPgProgrammer|Programmer's Guide"}}