Single Phase Constructor

Single phase constructor is to push a pointer to the clean-up stack, and then complete its construction. It uses the macro CONSTRUCTORS_MAY_LEAVE that is necessary to ensure whether the cleanup is correctly handled in the event that a constructor may leave beneath a call to new(ELeave).

Example

The following code snippet implies the usage of single phase constructor using CONSTRUCTORS_MAY_LEAVE macro.

- class CManagedUserSinglePhase : public CBase - { - public: - CONSTRUCTORS_MAY_LEAVE - static CManagedUserSinglePhase* NewL(CTicker* aTicker) - { - return new(ELeave) CManagedUserSinglePhase(aTicker); - } - } + + + + + +Single Phase Constructor

Characteristics of single phase constructor

The following are the major characteristics of single phase constructor:

The implementation of NewL becomes much simpler
By using RAII classes in fields to manage owned resources, constructor exception-safety can be maintained
Cleanup stack technology

Example

The following code snippet implies the usage of single phase constructor using CONSTRUCTORS_MAY_LEAVE macro.

+ class CManagedUserSinglePhase : public CBase + { + public: + CONSTRUCTORS_MAY_LEAVE + static CManagedUserSinglePhase* NewL(CTicker* aTicker) + { + return new(ELeave) CManagedUserSinglePhase(aTicker); + } + }