C++ language

This is a brief reference of available C++ language constructs.

Flow control

Conditional execution statements

Conditional statements execute different code paths according to the value of given expression.

• if executes code conditionally
• switch executes code according to the value of an integral argument

Iteration statements

Iteration statements execute a code path multiple times.

• for executes loops by specifying initialization, comparison, and increment
• range-for executes loops over a range (since C++11)
• while executes loop, checking condition before each iteration
• do-while executes loop, checking condition after each iteration

Jump statements

Jump statements continue program execution at a different location.

• continue skips the remaining part of the enclosing loop body
• break terminates the enclosing loop
• goto continues execution in another location
• return terminates execution of the enclosing function

Functions

The same code can be reused at different locations in the program.

• function declaration declares a function
• lambda function declaration declares a lambda function (since C++11)
• function template declares a function template
• inline specifier hints that the compiler insert a function's body directly into the calling code
• exception specifications declares that a function throws only specific exceptions (deprecated)
• noexcept specifier declares whether or not a function throws any exceptions (since C++11)

Exceptions

Exceptions are a more robust way to signal error condition than function return codes or global error variables.

• throw expression signals an error and transfers control to error handler
• try-catch block catches exceptions originating from specific block of code
• noexcept specifier and noexcept operator define and test if expressions throw exceptions (since C++11)

Namespaces

Namespaces provide a way to prevent name clashes in large projects.

• namespace declaration declares a namespace
• namespace aliases declares another name for an existing namespace

Types

• fundamental types define basic character, integer and floating point types
• pointer types define types holding a memory location
• compound types define types that hold several data members (essentially the same as class)
• enumeration types define types that are able to hold only one of the specified values
• union types define types that can hold data in several representations
• function types define function call signatures, that is the types of arguments and the return type
• decltype specifier defines a type equivalent to the type of an expression (since C++11)

Specifiers

• cv specifiers specifies constness and volatility of a type
• storage duration specifiers specifies storage duration of a type
• constexpr specifier specifies that the value of a variable or function can be computed at compile time (since C++11)
• auto specifier specifies that the actual type shall be defined from the expression, assigned to the variable (since C++11)
• alignas specifier specifies that the storage for the variable should be aligned by specific amount (since C++11)

Literals

Literals are the tokens of a C++ program that represent constant values, embedded in the source code.

• integer literals are decimal, octal, or hexadecimal numbers of integer type.
• character literals are individual characters of type char, char16_t, char32_t, or wchar_t
• floating-point literals are values of type float, double, or long double
• string literals are sequences of characters, which may be narrow, multibyte, or wide
• boolean literals are values of type bool, that is true and false
• nullptr is the pointer literal which specifies a null pointer value (since C++11)
• user-defined literals are constant values of user-specified type (since C++11)

Expressions

An expression is a sequence of operators and operands that specifies a computation. An expression can result in a value and can cause side effects.

• value categories (lvalue, rvalue, glvalue, prvalue, xvalue) classify expressions by their values
• order of evaluation of arguments and subexpressions specified the order in which intermediate results are obtained
• operators allow the use of syntax commonly found in mathematics

Common operators
assignment	increment decrement	arithmetic	logical	comparison	member access	other
a = b a = rvalue a += b a -= b a *= b a /= b a %= b a &= b a |= b a ^= b a <<= b a >>= b	++a --a a++ a--	+a -a a + b a - b a * b a / b a % b ~a a & b a | b a ^ b a << b a >> b	!a a && b a || b	a == b a != b a < b a > b a <= b a >= b	a[b] *a &a a->b a.b a->*b a.*b	a(...) a, b (type) a ? :
Special operators
static_cast converts one type to another compatible type dynamic_cast converts virtual base class to derived class const_cast converts type to compatible type with different cv qualifiers reinterpret_cast converts type to incompatible type new allocates memory delete deallocates memory sizeof queries the size of a type sizeof... queries the size of a parameter pack (since C++11) typeid queries the type information of a type noexcept checks if an expression can throw an exception (since C++11) alignof queries alignment requirements of a type (since C++11)

• operator precedence the order in which operators are bound to their arguments
• alternative representations alternative spellings for some of the operators

Utilities

Types

• typedef declaration creates a synonym for a type
• type alias declaration creates a synonym for a type
• attributes defines additional information about variable (since C++11)

Casts

• standard conversions implicit conversions from one type to another
• const_cast conversion
• static_cast conversion
• dynamic_cast conversion
• reinterpret_cast conversion
• explicit cast conversion using C-style cast notation and functional notation

Memory allocation

• new expression allocates memory dynamically
• delete expression deallocates memory dynamically

Classes

Classes provide the concept of object-oriented programming in C++.

• class declaration declares a class
• this pointer links to the current instance of a class in member methods
• access specifiers determines visibility of class members
• friend specifier grants access privileges to private/protected parts for non-member classes or functions
• initializer lists initializes class member data

Class-specific function properties

• virtual function specifier declares that a function is virtual
• override specifier declares that a virtual function overrides another virtual function.(since C++11)
• final specifier declares that a virtual function can not be overridden in a inheriting class.(since C++11)
• explicit function specifier declares that a constructor or conversion operator can not be used in implicit conversions (since C++11)
• static function specifier declares that a function does not use class data
• cv function specifier declares that a member function can only be used on cv qualified objects

Special member functions

• default constructor initializes the object with default contents
• copy constructor initializes the object with the contents of another object
• move constructor initializes the object with the contents of other, temporary object, minimizing copying overhead (since C++11)
• assignment operator replaces the contents of the object with the contents of another object
• move assignment operator replaces the contents of the object with the contents of other, temporary object, minimizing copying overhead (since C++11)
• destructor releases claimed resources

Templates

Allows functions and classes to operate on generic types

• class template declaration declares a class template
• function template declaration declares a function template
• template specialization defines an existing template for a specific type
• parameter packs allows the use of lists of types in templates (since C++11)

Miscellaneous

• Inline assembly allows the use of assembly code alongside C++ code