[c + +] In-class initializer

C++11 introduced serveral contructor-related enhancements including:

• Class member initializers
• Delegating controctors

This article discusses is about Class member initializers Only.

Class member initializers is also called In-class Initializers. C++11 follows other programming language so let's initializer a class member directly during its declaration:

// c++11    int 5;    // In-class initializer    bool flag (false);    // another in-class initializer  public :    M ();}; M m1;     // M1.J = 5, M1.flag = False

The complier transforms every member initializers (such as int j = 5) into a controctor ' s member Initializer. Therefore, the Declaration of class M above is semantically equalment to the following c++03 class Definition:

class m2{    int  j;     BOOL flag;  public :    M2 (): J (5), flag (false) {}}

If The constructor includes an explict member initializer for a member that also have an in-class initializer, the CONTROCT or ' s member Intializer would override the In-class Initializer.

class m2{    int7;    // In-class initializer  public :    M2 ();     // j = 7    M2 (int i): J (i) {}    //  overrides J ' s In-class intializer}; M2 m2;      // j = 7 M2 m3 (5);    // j = 5

Reference:

C++11 tutorial:new Constructor Features that make Object initialization Faster and smoother, smartbear.com

[c + +] In-class initializer