access specifiers

 

C++

Language

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

C++ language

General topics
Preprocessor
Comments
Keywords
ASCII chart
Escape sequences
History of C++
Flow control
Conditional execution statements
if statement	switch statement
Iteration statements
for loop range-for loop (C++11)	while loop do-while loop
Jump statements
continue statement break statement	goto statement return statement
Functions
function declaration
lambda function declaration
function template
inline specifier
exception specifications (deprecated)
noexcept specifier (C++11)
Exceptions
throw expression	try-catch block
Namespaces
namespace declaration	namespace aliases
Types
fundamental types compound types enumeration types	union types function types
decltype specifier (C++11)
Specifiers
cv specifiers
storage duration specifiers
constexpr specifier (C++11)
auto specifier (C++11)
alignas specifier (C++11)
Literals
integer literals character literals floating-point literals string literals	boolean literals nullptr (C++11) user-defined (C++11)
Expressions
value categories order of evaluation	operators operator precedence
alternative representations
Utilities
Types
typedef declaration
type alias declaration (C++11)
attributes (C++11)
Casts
implicit conversions
const_cast conversion
static_cast conversion
dynamic_cast conversion
reinterpret_cast conversion
C-style and functional cast
Memory allocation
new expression	delete expression
Classes
class declaration this pointer access specifiers	friend specifier initializer lists
Class-specific function properties
virtual function override specifier (C++11) final specifier (C++11)	explicit (C++11) static
Special member functions
default constructor copy constructor move constructor (C++11)	copy assignment move assignment (C++11) destructor
Templates
class template
function template
template specialization
parameter packs (C++11)
Miscellaneous
Inline assembly

 

In a class or struct body define the visibility of following declarators In a inheritance list, define the maximum visibility of inherited members

Syntax

public: declarators	(1)
protected: declarators	(2)
private: declarators	(3)
class identifier : public class_name	(4)
class identifier : protected class_name	(5)
class identifier : private class_name	(6)

Explanation

1. The symbols declared after the specifier have public accessibility
2. The symbols declared after the specifier have protected accessibility
3. The symbols declared after the specifier have private accessibility
4. The inherited members have the same accessibility as the base class ( either protected or public as private won't be visible in the derived class )
5. The inherited members have protected accessibility in the derived class
6. The inherited members have private accessibility in the derived class

Member accessibility by specifier

public

public members are accessible everywhere, within and outside the class scope

protected

protected members are accessible within the class and its methods and in its descendants

private

private members can be only accessed within the class and its methods

To grant access to external functions or classes to protected or private members, a friendship declaration must be present in the class body

Inherited private members are still present in the class data but cannot be accessed directly

A class has default private accessibility for inheritance and members, a struct has instead a default public accessibility