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Where to find unnamed namespaces in cppreference?


Asked by Caden Stevens on Dec 08, 2021 FAQ



3) Unnamed namespace definition. Its members have potential scope from their point of declaration to the end of the translation unit, and have internal linkage. 4) Namespace names (along with class names) can appear on the left hand side of the scope resolution operator, as part of qualified name lookup.
Indeed,
From within the namespace, all identifiers are referenced as usual. However, if one wants to refer to the identifiers from outside the namespace, the namespace prefix nmname::must be prepended, where nmnameis the name of the namespace. See the example below:
In addition, Using-declarations can be used to introduce namespace members into other namespaces and block scopes, or to introduce base class members into derived class definitions, or to introduce enumerators into namespaces, block, and class scopes (since C++20) .
In fact,
Instead of an immutable prefix to the identifier names, namespaces introduce a new, named scope. From within the namespace, all identifiers are referenced as usual. However, if one wants to refer to the identifiers from outside the namespace, the namespace prefix nmname::must be prepended, where nmnameis the name of the namespace.
Next,
Namespaces are an elegant solution to the problem. Instead of an immutable prefix to the identifier names, namespaces introduce a new, named scope. From within the namespace, all identifiers are referenced as usual.