Struct inheritance in C++

c++ inheritance struct

186,975

Solution 1

Yes, struct is exactly like class except the default accessibility is public for struct (while it's private for class).

Solution 2

Yes. The inheritance is public by default.

Syntax (example):

struct A { };
struct B : A { };
struct C : B { };

Solution 3

Other than what Alex and Evan have already stated, I would like to add that a C++ struct is not like a C struct.

In C++, a struct can have methods, inheritance, etc. just like a C++ class.

Solution 4

In C++, a structure's inheritance is the same as a class except the following differences:

When deriving a struct from a class/struct, the default access-specifier for a base class/struct is public. And when deriving a class, the default access specifier is private.

For example, program 1 fails with a compilation error and program 2 works fine.

// Program 1
#include <stdio.h>

class Base {
    public:
        int x;
};

class Derived : Base { }; // Is equivalent to class Derived : private Base {}

int main()
{
    Derived d;
    d.x = 20; // Compiler error because inheritance is private
    getchar();
    return 0;
}

// Program 2
#include <stdio.h>

struct Base {
    public:
        int x;
};

struct Derived : Base { }; // Is equivalent to struct Derived : public Base {}

int main()
{
    Derived d;
    d.x = 20; // Works fine because inheritance is public
    getchar();
    return 0;
}

Solution 5

Of course. In C++, structs and classes are nearly identical (things like defaulting to public instead of private are among the small differences).

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Peter Mortensen

Experienced application developer. Software Engineer. M.Sc.E.E. C++ (10 years), software engineering, .NET/C#/VB.NET (12 years), usability testing, Perl, scientific computing, Python, Windows/Macintosh/Linux, Z80 assembly, CAN bus/CANopen. Contact I can be contacted through this reCAPTCHA (requires JavaScript to be allowed from google.com and possibly other(s)). Make sure to make the subject specific (I said: specific. Repeat: specific subject required). I can not stress this enough - 90% of you can not compose a specific subject, but instead use some generic subject. Use a specific subject, damn it! You still don't get it. It can't be that difficult to provide a specific subject to an email instead of a generic one. For example, including meta content like "quick question" is unhelpful. Concentrate on the actual subject. Did I say specific? I think I did. Let me repeat it just in case: use a specific subject in your email (otherwise it will no be opened at all). Selected questions, etc.: End-of-line identifier in VB.NET? How can I determine if a .NET assembly was built for x86 or x64? C++ reference - sample memmove The difference between + and & for joining strings in VB.NET Some of my other accounts: Careers. [/]. Super User (SU). [/]. Other My 15 minutes of fame on Super User My 15 minutes of fame in Denmark Blog. Sample: Jump the shark. LinkedIn @PeterMortensen (Twitter) Quora GitHub Full jump page (Last updated 2021-11-25)

Updated on August 04, 2020

Comments

Peter Mortensen almost 4 years

Can a struct be inherited in C++?
camh about 15 years

a C++ struct can be like a C struct. When it is, its called a POD - Plain Old Datatype. It is an important distinction, since for example, only POD structs can be part of unions.
RL-S about 4 years

If it's a POD, it doesn't have methods. Otherwise the name is meaningless.
lil' wing over 3 years

This is even the case in C++98, which I was surprised to learn, since all of my C++ textbooks leave out struct inheritance.