c_namespaces

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c_namespaces [2018/02/01 11:07] – [Unnamed namespaces] rpjdayc_namespaces [2018/02/01 14:50] (current) – [using-Directives] rpjday
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 namespace ATT = American_Telephone_and_Telegraph; // namespace alias namespace ATT = American_Telephone_and_Telegraph; // namespace alias
 </code> </code>
 +
 +Also, namespace identifier is "... either a previously unused identifier, in which case this is //original-namespace-definition// or the name of a namespace, in which case this is //extension-namespace-definition//."
  
 ===== Extensibility (namespaces are "open") ===== ===== Extensibility (namespaces are "open") =====
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 ==== using-Declarations ==== ==== using-Declarations ====
 +
 +Read [[http://en.cppreference.com/w/cpp/language/namespace#Using-declarations|this]] carefully.
  
 "makes the symbol name from the namespace ns_name accessible for unqualified lookup as if declared in the same class scope, block scope, or namespace as where this using-declaration appears." "makes the symbol name from the namespace ns_name accessible for unqualified lookup as if declared in the same class scope, block scope, or namespace as where this using-declaration appears."
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 } }
 </code> </code>
 +
 +Useful for introducing base class members into derived class definitions.
  
 ==== using-Directives ==== ==== using-Directives ====
 +
 +cppreference.com link [[http://en.cppreference.com/w/cpp/language/namespace#Using-directives|here]].
  
 "From the point of view of unqualified name lookup of any name after a using-directive and until the end of the scope in which it appears, every name from ns_name is visible as if it were declared in the nearest enclosing namespace which contains both the using-directive and ns_name." "From the point of view of unqualified name lookup of any name after a using-directive and until the end of the scope in which it appears, every name from ns_name is visible as if it were declared in the nearest enclosing namespace which contains both the using-directive and ns_name."
  • c_namespaces.1517483273.txt.gz
  • Last modified: 2018/02/01 11:07
  • by rpjday