Punctuation

These are the punctuation symbols in C++. The meaning of each symbol is detailed in the linked pages.

`{` `}`

In a class/struct or union definition, delimit the member specification.
In a enum definition, delimit the enumerator list.
Delimit a compound statement. The compound statement may be part of

In initialization, delimit the initializers. This kind of initialization is called list-initialization. (since C++11)
In a namespace definition, delimit the namespace body.
In a language linkage specification, delimit the declarations.
In a requires-expression, delimit the requirements. (since C++20)
In a compound requirement, delimit the expression. (since C++20)
In a export declaration, delimit the declarations. (since C++20)

`[` `]`

Subscript operator; part of operator[] in operator overloading.
Part of array declarator in a declaration or a type-id (e.g. in a new expression)
Part of new[] operator in operator overloading (allocation function).
Part of delete[] operator in delete expression and operator overloading (deallocation function).
In a lambda expression, delimit the captures. (since C++11)
In a attribute specifier, delimit the attributes. (since C++11)
In a structured binding declaration, delimit the identifier list. (since C++17)

`#`

Introduce a preprocessing directive.
The preprocessing operator for stringification.

`##`

The preprocessing operator for token pasting.

`(` `)`

In a expression, indicate grouping.
Function call operator; part of operator() in operator overloading.
In a function-style type cast, delimit the expression/initializers.
In a static_cast, const_cast, reinterpret_cast, or dynamic_cast, delimit the expression.
In a typeid, sizeof, sizeof..., alignof, or noexcept (since C++11) expression, delimit the operand.
In a placement new expression, delimit the placement arguments.
In a new expression, optionally delimit the type-id.
In a new expression, delimit the initializers.
In a C-style cast, delimit the type-id.
In a declaration or a type-id, indicate grouping.
Delimit the parameter list in

a function declarator (in a declaration or a type-id)
a lambda expression (since C++11)
a user-defined deduction guide (since C++17)
a requires-expression (since C++20)

In direct-initialization, delimit the initializers.
In a asm declaration, delimit the string literal.
In a member initializer list, delimit the initializers to a base or member.
In a if (including constexpr if) (since C++17), switch, while, do-while, or for (including range-based for) (since C++11) statement, delimit the controlling clause.
In a catch clause, delimit the parameter declaration.
In a function-like macro definition, delimit the macro parameters.
Part of a defined, __has_include (since C++17), __has_cpp_attribute (since C++20) preprocessing operator.
In a static_assert declaration, delimit the operands. (since C++11)
In a decltype specifier, noexcept specifier, alignas specifier, conditional explicit specifier (since C++20), delimit the operand. (since C++11)
In a attribute, delimit the attribute arguments. (since C++11)
Part of decltype(auto) specifier. (since C++14)
Delimit a fold expression. (since C++17)
Part of __VA_OPT__ replacement in a variadic macro definition. (since C++20)

`;`

Indicate the end of

a statement (including the init-statement of a for statement)
a declaration or member declaration
a module declaration, import declaration, global module fragment introducer, or private module fragment introducer (since C++20)
a requirement (since C++20)

Separate the second and third clauses of a for statement.

`:`

Part of conditional operator.
Part of label declaration.
In the class-head of a class definition, introduce the base-clause.
Part of access specifier in member specification.
In a bit-field member declaration, introduce the width.
In a constructor definition, introduce the member initializer list.
In a range-based for statement, separate the range-declaration and the range-initializer. (since C++11)
Introduce a enum base, which specifies the underlying type of the enum. (since C++11)
In a attribute specifier, separate the attribute-using-prefix and the attribute list. (since C++17)
In a module declaration or import declaration of module partition, introduce the module partition name. (since C++20)
Part of a private module fragment introducer (module :private;). (since C++20)

`...`

In the parameter list of a function declarator or lambda expression (since C++11) or user-defined deduction guide (since C++17), signify a variadic function.
In a catch-clause, signify catch-all handler.
In a macro definition, signify a variadic macro. (since C++11)
Indicate pack declaration and expansion. (since C++11)

`?`

Part of conditional operator.

`::`

Scope resolution operator in

a qualified name
a pointer-to-member declaration
a new or delete expression, to indicate that only global allocation or deallocation functions are looked up

In a attribute, indicate attribute scope. (since C++11)
Part of nested namespace definition. (since C++17)

`.`

Member access operator.
In aggregate initialization, introduce a designator. (since C++20)
Part of module name or module partition name. (since C++20)

`.*`

Pointer-to-member access operator.

`->`

Member access operator; part of operator-> in operator overloading.
In a function declarator or lambda expression, introduce the trailing return type. (since C++11)
In a user-defined deduction guide, introduce the result type. (since C++17)
In a compound requirement, introduce the return type requirement. (since C++20)

`->*`

Pointer-to-member access operator; part of operator->* in operator overloading.

`~`

Unary complement operator (a.k.a. bitwise not operator); part of operator~ in operator overloading.
Part of a id-expression to name a destructor or pseudo-destructor.

`!`

Logical not operator; part of operator! in operator overloading.
Part of reversed variant of a consteval if statement. (since C++23)

`+`

Unary plus operator; part of operator+ in operator overloading.
Binary plus operator; part of operator+ in operator overloading.

`-`

Unary minus operator; part of operator- in operator overloading.
Binary minus operator; part of operator- in operator overloading.

`*`

Indirection operator; part of operator* in operator overloading.
Multiplication operator; part of operator* in operator overloading.
Pointer operator or part of pointer-to-member operator in a declarator or in a type-id.
Part of *this in a lambda capture list, to capture the current object by copy. (since C++17)

`/`

Division operator; part of operator/ in operator overloading.

`%`

Modulo operator; part of operator% in operator overloading.

`^`

Bitwise xor operator; part of operator^ in operator overloading.

`&`

Address-of operator; part of operator& in operator overloading.
Bitwise and operator; part of operator& in operator overloading.
Lvalue-reference operator in a declarator or in a type-id.
In a lambda capture, indicate by-reference capture. (since C++11)
Ref-qualifier in member function declaration. (since C++11)

`|`

Bitwise or operator; part of operator| in operator overloading.

`=`

Simple assignment operator; part of operator= in operator overloading, which might be a special member function (copy assignment operator or move assignment operator (since C++11)).
In initialization, indicate copy-initialization or copy-list-initialization (since C++11).
In a function declaration, introduce a default argument.
In a template parameter list, introduce a default template argument.
In a namespace alias definition, separate the alias and the aliased namespace.
In a enum definition, introduce the value of enumerator.
Part of pure-specifier in a pure virtual function declaration.
Capture default in lambda capture, to indicate by-copy capture. (since C++11)
Part of defaulted definition (=default;) or deleted definition (=delete;) in function definition. (since C++11)
In a type alias declaration, separate the alias and the aliased type. (since C++11)
In a concept definition, separate the concept name and the constraint expression. (since C++20)