CODEWITHSUNDEEP
c++
That Guy
That Guy

Reputation: 2399

Do member variables have external linkage?

I have read this and it says that

names of classes, their member functions, static data members (const or not), nested classes and enumerations, and functions first introduced with friend declarations inside class bodies

have external linkage by default.. But what about the variables declared inside the class body that are not specified static? Also, it starts out with

Any of the following names declared at namespace scope have external linkage

, but is class scope considered a namespace scope? I mean class scope and namespace scope are different, so why do they start out by saying that the following is applicable for the mentioned declared inside a namespace scope? I mean, for example, member functions are declared in class scope and they mention them as if it was namespace scope?

Upvotes: 4

Views: 871

Answers (2)

n. m. could be an AI
n. m. could be an AI

Reputation: 119877

Quote from the standard:

A name is said to have linkage when it might denote the same object, reference, function, type, template, namespace or value as a name introduced by a declaration in another scope

Translation to plain English:

If you can redeclare it in another scope, it has linkage. Otherwise, nope.

You cannot redeclare a non-static class data member in another scope, so it has no linkage.

Upvotes: -1

Aconcagua
Aconcagua

Reputation: 25526

Following example:

class C
{
public:
    int n;
};

C e;
namespace { C i; }

e has external linkage, i internal. How much sense would it make to speak of linkage of n now? If at all, you could consider n inheriting the linkage of the containing object, thus e.n would have external, i.n internal linkage – for better understanding only, I do not consider this as correct wording...

Upvotes: 2

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