| class keyword |
Declares a class or template parameter, or elaborates a type name
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class-specifier ::= class-head { [member-specification] }
class-head ::= class-key [identifier] [base-clause] |
class-key nested-name :: identifier [base-clause] |
class-key [nested-name ::] template-id [base-clause] class-key ::= class |
struct | union
member-specification ::= member-decl [member-specification] |
access-specifier : [member-specification]
member-decl ::= [decl-specifier-seq] [member-declarator-list] ; |
function-definition [;] | qualified-id ; | using-decl | template-decl
member-declarator-list ::= member-declarator |
member-declarator-list , member-declarator
member-declarator ::= declarator [= 0] | declarator [= constant-expression] |
[identifier] : constant-expression
base-clause ::= : base-specifier-list
base-specifier-list ::= base-specifier | base-specifier-list , base-specifier
base-specifier ::= [base-modifiers] [::] [nested-name ::] class-name
base-modifiers ::= virtual [access-specifier] | access-specifier [virtual]
access-specifier ::= private | protected | public
class-name ::= identifier | template-id
type-parm := class [identifier] [= type-id] |
template < template-parm-list > class [identifier] [= id-expression]
elaborated-type-specifier := class-key [::] [nested-name ::] identifier |
class-key [::] [nested-name ::] [template] template-id
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The class keyword introduces a class declaration
or definition, names a type template parameter
(type-parm), or names a class type in an
elaborated-type-specifier. In a
class definition, the only difference between
class and struct is that the
default access level is private for class and
public for struct.
When declaring a type template parameter,
typename and class are
interchangeable.
Example
template<class T> // Can use typename instead of class
class point {
public:
point(T x = 0, T y = 0);
private:
T x_, y_;
};
point<int> pt1;
class point<int> pt2; // redundant use of class
See Also
declaration, declarator,
expression, function,
identifier, private,
protected, public,
struct, template,
type, typename,
union, virtual, Chapter 6, Chapter 7
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