Builder Mode C ++ implementation

Recently I learned the design pattern by myself and found that many books are implemented in java. Because I am engaged in C ++ development, I want to use C ++ to implement it myself and deepen my understanding.

Creator Mode

Definition: separates the construction of a complex object from its representation, so that different representations can be created during the same construction process.

Applicability:

1. When creating complex objects, algorithms should be independent of the components of the objects and their assembly methods

2. When the constructor must run a different representation of the constructed object

Structure diagram:

Implementation:

Class Product

{

Public:

VoidSetPartA (int val)

{

M_partA = val;

}

VoidSetPartB (int val)

{

M_partB = val;

}

VoidSetPartC (int val)

{

M_partC = val;

}

VoidshowProperty ()

{

Cout <"show product property:" <

Cout <"m_partA:" <

Cout <"m_partB:" <

Cout <"m_partC:" <

}

Protected:

Private:

Intm_partA;

Intm_partB;

Intm_partC;

};

// Builder does not declare the method as a pure virtual function, so that the customer only needs to redefine the operations of interest.

Class Builder

{

Public:

Virtual void CreateProduct (){};

Virtual void SetPartA (intval ){};

Virtual void SetPartB (intval ){};

Virtual void SetPartC (intval ){};

VirtualProduct * GetProduct ()

{

ReturnNULL;

};

};

Class ConcreteBuilder: public Builder

{

Public:

VoidCreateProduct ()

{

M_product = new Product;

}

VoidSetPartA (int val)

{

Cout <"Build PartA" <

M_product-> SetPartA (val );

}

VoidSetPartB (int val)

{

Cout <"Build PartB" <

M_product-> SetPartB (val );

}

VoidSetPartC (int val)

{

Cout <"Build PartC" <

M_product-> SetPartC (val );

}

Product * GetProduct ()

{

Returnm_product;

}

Protected:

Private:

Product * m_product;

};

Class Director

{

Public:

Director (Builder * buider)

{

M_pBuilder = buider;

}

VoidConstruct ()

{

If (! M_pBuilder)

{

Return;

}

M_pBuilder-> CreateProduct ();

M_pBuilder-> SetPartA (1 );

M_pBuilder-> SetPartB (2 );

M_pBuilder-> SetPartC (3 );

}

Protected:

Private:

Builder * m_pBuilder;

};

Builder * pBuilder = new ConcreteBuilder;

Director * pDirector = new Director (pBuilder );

PDirector-> Construct ();

Product * product = pBuilder-> GetProduct ();

Product-> showProperty ();