Scope resolution operator
不同的programming language使用的scope resolution operator是不同的。
wikipedia Scope resolution operator
In computer programming, scope is an enclosing context where values and expressions are associated. The scope resolution operator helps to identify and specify the context to which an identifier refers, particularly by specifying a namespace. The specific uses vary across different programming languages with the notions of scoping. In many languages, the scope resolution operator is written ::
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