tmp/tmpkoiri2a7/{from.md → to.md}
RENAMED
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## Nested class declarations <a id="class.nest">[[class.nest]]</a>
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A class can be declared within another class. A class declared within
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another is called a *nested* class. The name of a nested class is local
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to its enclosing class. The nested class is in the scope of its
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enclosing class.
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``` cpp
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int x;
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int y;
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@@ -29,40 +33,50 @@ struct enclose {
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};
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inner* p = 0; // error: inner not in scope
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```
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Member functions and static data members of a nested class can be
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defined in a namespace scope enclosing the definition of their class.
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``` cpp
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struct enclose {
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struct inner {
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static int x;
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void f(int i);
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};
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};
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int enclose::inner::x = 1;
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void enclose::inner::f(int i) {
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```
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If class `X` is defined in a namespace scope, a nested class `Y` may be
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declared in class `X` and later defined in the definition of class `X`
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or be later defined in a namespace scope enclosing the definition of
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class `X`.
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``` cpp
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class E {
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class I1; // forward declaration of nested class
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class I2;
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class I1 { }; // definition of nested class
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};
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class E::I2 { }; // definition of nested class
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```
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Like a member function, a friend function ([[class.friend]]) defined
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within a nested class is in the lexical scope of that class; it obeys
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the same rules for name binding as a static member function of that
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class ([[class.static]]), but it has no special access rights to
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members of an enclosing class.
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### Nested class declarations <a id="class.nest">[[class.nest]]</a>
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A class can be declared within another class. A class declared within
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another is called a *nested* class. The name of a nested class is local
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to its enclosing class. The nested class is in the scope of its
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enclosing class.
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[*Note 1*: See [[expr.prim]] for restrictions on the use of non-static
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data members and non-static member functions. — *end note*]
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[*Example 1*:
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``` cpp
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int x;
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int y;
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};
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inner* p = 0; // error: inner not in scope
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```
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— *end example*]
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Member functions and static data members of a nested class can be
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defined in a namespace scope enclosing the definition of their class.
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[*Example 2*:
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``` cpp
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struct enclose {
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struct inner {
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static int x;
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void f(int i);
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};
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};
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int enclose::inner::x = 1;
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void enclose::inner::f(int i) { ... }
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```
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— *end example*]
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If class `X` is defined in a namespace scope, a nested class `Y` may be
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declared in class `X` and later defined in the definition of class `X`
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or be later defined in a namespace scope enclosing the definition of
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class `X`.
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[*Example 3*:
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``` cpp
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class E {
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class I1; // forward declaration of nested class
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class I2;
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class I1 { }; // definition of nested class
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};
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class E::I2 { }; // definition of nested class
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```
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— *end example*]
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Like a member function, a friend function ([[class.friend]]) defined
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within a nested class is in the lexical scope of that class; it obeys
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the same rules for name binding as a static member function of that
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class ([[class.static]]), but it has no special access rights to
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members of an enclosing class.
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