More efficient C ++ Reading Notes 4

Item 4: avoid useless Default constructors

 

 

No default constructor will cause:

1. the array form of the class cannot be created.

2. It cannot be used in many template-based container classes.

 

 

The dilemma of providing Default constructors or not providing Default constructors when designing a virtual base class:

1. It is difficult to cooperate with virtual base classes that do not provide Default constructors. Because almost all derived classes must provide parameters to the virtual base class constructor during instantiation.

2. Providing meaningless Default constructors also affects the efficiency of classes.