C++ドメイン

Added in version 1.0.

C++ドメインは(cpp)は、C++プロジェクトのドキュメント作成をサポートします。

Directives for Declaring Entities

以下のディレクティブを使用できます。全ての定義にはアクセス制御識別子(public, private, protected)を最初に付けられます。

.. cpp:class:: class specifier
.. cpp:struct:: class specifier

クラスや構造について説明します。継承についての情報も書けます。

.. cpp:class:: MyClass : public MyBase, MyOtherBase

The difference between cpp:class and cpp:struct is only cosmetic: the prefix rendered in the output, and the specifier shown in the index.

クラスはネストしたスコープの中で直接宣言することができます、 例として

.. cpp:class:: OuterScope::MyClass : public MyBase, MyOtherBase

クラステンプレートは以下のように定義することができます:

.. cpp:class:: template<typename T, std::size_t N> std::array

もしくは改行を用いて:

.. cpp:class:: template<typename T, std::size_t N> \
               std::array

完全な、もしくは一部のテンプレートの専門化は次のように宣言できます:

.. cpp:class:: template<> \
               std::array<bool, 256>

.. cpp:class:: template<typename T> \
               std::array<T, 42>

Added in version 2.0: The cpp:struct directive.

.. cpp:function:: (member) function prototype

関数とメンバーの説明です。例えば以下のように書きます:

.. cpp:function:: bool myMethod(int arg1, std::string arg2)

   A function with parameters and types.

.. cpp:function:: bool myMethod(int, double)

   A function with unnamed parameters.

.. cpp:function:: const T &MyClass::operator[](std::size_t i) const

   An overload for the indexing operator.

.. cpp:function:: operator bool() const

   A casting operator.

.. cpp:function:: constexpr void foo(std::string &bar[2]) noexcept

   A constexpr function.

.. cpp:function:: MyClass::MyClass(const MyClass&) = default

   A copy constructor with default implementation.

Functionテンプレートは次のようにも表現できます:

.. cpp:function:: template<typename U> \
                  void print(U &&u)

and function template specialisations:

.. cpp:function:: template<> \
                  void print(int i)
:single-line-parameter-list: (no value)

Ensures that the function's parameters will be emitted on a single logical line, overriding cpp_maximum_signature_line_length and maximum_signature_line_length.

Added in version 7.1.

.. cpp:member:: (member) variable declaration
.. cpp:var:: (member) variable declaration

変数とメンバー変数の説明です。例えば以下のように書きます:

.. cpp:member:: std::string MyClass::myMember

.. cpp:var:: std::string MyClass::myOtherMember[N][M]

.. cpp:member:: int a = 42

変数テンプレートは次のようにも表現できます:

.. cpp:member:: template<class T> \
                constexpr T pi = T(3.1415926535897932385)
.. cpp:type:: typedef declaration
.. cpp:type:: name
.. cpp:type:: type alias declaration

Describe a type as in a typedef declaration, a type alias declaration, or simply the name of a type with unspecified type, e.g.,:

.. cpp:type:: std::vector<int> MyList

   A typedef-like declaration of a type.

.. cpp:type:: MyContainer::const_iterator

   Declaration of a type alias with unspecified type.

.. cpp:type:: MyType = std::unordered_map<int, std::string>

   Declaration of a type alias.

エイリアス型は次のようにも宣言が可能です:

.. cpp:type:: template<typename T> \
              MyContainer = std::vector<T>

その例は次のように出力されます。

typedef std::vector<int> MyList

A typedef-like declaration of a type.

type MyContainer::const_iterator

Declaration of a type alias with unspecified type.

using MyType = std::unordered_map<int, std::string>

Declaration of a type alias.

template<typename T>
using MyContainer = std::vector<T>
.. cpp:enum:: unscoped enum declaration
.. cpp:enum-struct:: scoped enum declaration
.. cpp:enum-class:: scoped enum declaration

Describe a (scoped) enum, possibly with the underlying type specified. Any enumerators declared inside an unscoped enum will be declared both in the enum scope and in the parent scope. Examples:

.. cpp:enum:: MyEnum

   An unscoped enum.

.. cpp:enum:: MySpecificEnum : long

   An unscoped enum with specified underlying type.

.. cpp:enum-class:: MyScopedEnum

   A scoped enum.

.. cpp:enum-struct:: protected MyScopedVisibilityEnum : std::underlying_type<MySpecificEnum>::type

   A scoped enum with non-default visibility, and with a specified
   underlying type.
.. cpp:enumerator:: name
.. cpp:enumerator:: name = constant

列挙子について説明します。値指定もできます。例:

.. cpp:enumerator:: MyEnum::myEnumerator

.. cpp:enumerator:: MyEnum::myOtherEnumerator = 42
.. cpp:union:: name

Describe a union.

Added in version 1.8.

.. cpp:concept:: template-parameter-list name

警告

The support for concepts is experimental. It is based on the current draft standard and the Concepts Technical Specification. The features may change as they evolve.

Describe a concept. It must have exactly 1 template parameter list. The name may be a nested name. Example:

.. cpp:concept:: template<typename It> std::Iterator

   Proxy to an element of a notional sequence that can be compared,
   indirected, or incremented.

   **Notation**

   .. cpp:var:: It r

      An lvalue.

   **Valid Expressions**

   - :cpp:expr:`*r`, when :cpp:expr:`r` is dereferenceable.
   - :cpp:expr:`++r`, with return type :cpp:expr:`It&`, when
     :cpp:expr:`r` is incrementable.

This will render as follows:

template<typename It>
concept std::Iterator

Proxy to an element of a notional sequence that can be compared, indirected, or incremented.

Notation

It r

An lvalue.

Valid Expressions

  • *r, when r is dereferenceable.

  • ++r, with return type It&, when r is incrementable.

Added in version 1.5.

オプション

Some directives support options:

  • :no-index-entry: and :no-contents-entry:, see マークアップの基礎.

  • :tparam-line-spec:, for templated declarations. If specified, each template parameter will be rendered on a separate line.

    Added in version 1.6.

Anonymous Entities

C++ supports anonymous namespaces, classes, enums, and unions. For the sake of documentation they must be given some name that starts with @, e.g., @42 or @data. These names can also be used in cross-references and (type) expressions, though nested symbols will be found even when omitted. The @... name will always be rendered as [anonymous] (possibly as a link).

サンプル:

.. cpp:class:: Data

   .. cpp:union:: @data

      .. cpp:var:: int a

      .. cpp:var:: double b

Explicit ref: :cpp:var:`Data::@data::a`. Short-hand ref: :cpp:var:`Data::a`.

This will be rendered as:

class Data
union [anonymous]
int a
double b

Explicit ref: Data::[anonymous]::a. Short-hand ref: Data::a.

Added in version 1.8.

Aliasing Declarations

Sometimes it may be helpful list declarations elsewhere than their main documentation, e.g., when creating a synopsis of a class interface. The following directive can be used for this purpose.

.. cpp:alias:: name or function signature

Insert one or more alias declarations. Each entity can be specified as they can in the cpp:any role. If the name of a function is given (as opposed to the complete signature), then all overloads of the function will be listed.

例えば:

.. cpp:alias:: Data::a
               overload_example::C::f

becomes

int a
void f(double d) const
void f(double d)
void f(int i)
void f()

whereas:

.. cpp:alias:: void overload_example::C::f(double d) const
               void overload_example::C::f(double d)

becomes

void f(double d) const
void f(double d)

Added in version 2.0.

オプション

:maxdepth: int

Insert nested declarations as well, up to the total depth given. Use 0 for infinite depth and 1 for just the mentioned declaration. Defaults to 1.

Added in version 3.5.

:noroot:

Skip the mentioned declarations and only render nested declarations. Requires maxdepth either 0 or at least 2.

Added in version 3.5.

Constrained Templates

警告

The support for concepts is experimental. It is based on the current draft standard and the Concepts Technical Specification. The features may change as they evolve.

注釈

Sphinx does not currently support requires clauses.

Placeholders

Declarations may use the name of a concept to introduce constrained template parameters, or the keyword auto to introduce unconstrained template parameters:

.. cpp:function:: void f(auto &&arg)

   A function template with a single unconstrained template parameter.

.. cpp:function:: void f(std::Iterator it)

   A function template with a single template parameter, constrained by the
   Iterator concept.

Template Introductions

Simple constrained function or class templates can be declared with a template introduction instead of a template parameter list:

.. cpp:function:: std::Iterator{It} void advance(It &it)

    A function template with a template parameter constrained to be an
    Iterator.

.. cpp:class:: std::LessThanComparable{T} MySortedContainer

    A class template with a template parameter constrained to be
    LessThanComparable.

They are rendered as follows.

std::Iterator{It}
void advance(It &it)

A function template with a template parameter constrained to be an Iterator.

std::LessThanComparable{T}
class MySortedContainer

A class template with a template parameter constrained to be LessThanComparable.

Note however that no checking is performed with respect to parameter compatibility. E.g., Iterator{A, B, C} will be accepted as an introduction even though it would not be valid C++.

Inline Expressions and Types

:cpp:expr:
:cpp:texpr:

Insert a C++ expression or type either as inline code (cpp:expr) or inline text (cpp:texpr). For example:

.. cpp:var:: int a = 42

.. cpp:function:: int f(int i)

An expression: :cpp:expr:`a * f(a)` (or as text: :cpp:texpr:`a * f(a)`).

A type: :cpp:expr:`const MySortedContainer<int>&`
(or as text :cpp:texpr:`const MySortedContainer<int>&`).

will be rendered as follows:

int a = 42
int f(int i)

An expression: a * f(a) (or as text: a * f(a)).

A type: const MySortedContainer<int>& (or as text const MySortedContainer<int>&).

Added in version 1.7: The cpp:expr role.

Added in version 1.8: The cpp:texpr role.

名前空間

Declarations in the C++ domain are as default placed in global scope. The current scope can be changed using three namespace directives. They manage a stack declarations where cpp:namespace resets the stack and changes a given scope.

The cpp:namespace-push directive changes the scope to a given inner scope of the current one.

The cpp:namespace-pop directive undoes the most recent cpp:namespace-push directive.

.. cpp:namespace:: scope specification

Changes the current scope for the subsequent objects to the given scope, and resets the namespace directive stack. Note that the namespace does not need to correspond to C++ namespaces, but can end in names of classes, e.g.,:

.. cpp:namespace:: Namespace1::Namespace2::SomeClass::AnInnerClass

All subsequent objects will be defined as if their name were declared with the scope prepended. The subsequent cross-references will be searched for starting in the current scope.

Using NULL, 0, or nullptr as the scope will change to global scope.

A namespace declaration can also be templated, e.g.,:

.. cpp:class:: template<typename T> \
               std::vector

.. cpp:namespace:: template<typename T> std::vector

.. cpp:function:: std::size_t size() const

declares size as a member function of the class template std::vector. Equivalently this could have been declared using:

.. cpp:class:: template<typename T> \
               std::vector

   .. cpp:function:: std::size_t size() const

or:

.. cpp:class:: template<typename T> \
               std::vector
.. cpp:namespace-push:: scope specification

Change the scope relatively to the current scope. For example, after:

.. cpp:namespace:: A::B

.. cpp:namespace-push:: C::D

the current scope will be A::B::C::D.

Added in version 1.4.

.. cpp:namespace-pop::

Undo the previous cpp:namespace-push directive (not just pop a scope). For example, after:

.. cpp:namespace:: A::B

.. cpp:namespace-push:: C::D

.. cpp:namespace-pop::

the current scope will be A::B (not A::B::C).

If no previous cpp:namespace-push directive has been used, but only a cpp:namespace directive, then the current scope will be reset to global scope. That is, .. cpp:namespace:: A::B is equivalent to:

.. cpp:namespace:: nullptr

.. cpp:namespace-push:: A::B

Added in version 1.4.

詳細情報フィールドのリスト

All the C++ directives for declaring entities support the following info fields (see also 詳細情報フィールドのリスト):

  • tparam: Description of a template parameter.

The cpp:function directive additionally supports the following fields:

  • param, parameter, arg, argument: Description of a parameter.

  • returns, return: Description of a return value.

  • retval, retvals: An alternative to returns for describing the result of the function.

  • throws, throw, exception: Description of a possibly thrown exception.

Added in version 4.3: The retval field type.

クロスリファレンス

These roles link to the given declaration types:

:cpp:any:
:cpp:class:
:cpp:struct:
:cpp:func:
:cpp:member:
:cpp:var:
:cpp:type:
:cpp:concept:
:cpp:enum:
:cpp:enumerator:

Reference a C++ declaration by name (see below for details). The name must be properly qualified relative to the position of the link.

Added in version 2.0: The cpp:struct role as alias for the cpp:class role.

Note on References with Templates Parameters/Arguments

These roles follow the Sphinx クロスリファレンス文法 rules. This means care must be taken when referencing a (partial) template specialization, e.g. if the link looks like this: :cpp:class:`MyClass<int>`. This is interpreted as a link to int with a title of MyClass. In this case, escape the opening angle bracket with a backslash, like this: :cpp:class:`MyClass\<int>`.

When a custom title is not needed it may be useful to use the roles for inline expressions, cpp:expr and cpp:texpr, where angle brackets do not need escaping.

Declarations without template parameters and template arguments

For linking to non-templated declarations the name must be a nested name, e.g., f or MyClass::f.

Overloaded (member) functions

When a (member) function is referenced using just its name, the reference will point to an arbitrary matching overload. The cpp:any and cpp:func roles use an alternative format, which simply is a complete function declaration. This will resolve to the exact matching overload. As example, consider the following class declaration:

class C
void f(double d) const
void f(double d)
void f(int i)
void f()

References using the cpp:func role:

Note that the add_function_parentheses configuration variable does not influence specific overload references.

Templated declarations

Assume the following declarations.

class Wrapper
template<typename TOuter>
class Outer
template<typename TInner>
class Inner

In general the reference must include the template parameter declarations, and template arguments for the prefix of qualified names. For example:

  • template\<typename TOuter> Wrapper::Outer (template<typename TOuter> Wrapper::Outer)

  • template\<typename TOuter> template\<typename TInner> Wrapper::Outer<TOuter>::Inner (template<typename TOuter> template<typename TInner> Wrapper::Outer<TOuter>::Inner)

Currently the lookup only succeed if the template parameter identifiers are equal strings. That is, template\<typename UOuter> Wrapper::Outer will not work.

As a shorthand notation, if a template parameter list is omitted, then the lookup will assume either a primary template or a non-template, but not a partial template specialisation. This means the following references work as well:

(Full) Template Specialisations

Assume the following declarations.

template<typename TOuter>
class Outer
template<typename TInner>
class Inner
template<>
class Outer<int>
template<typename TInner>
class Inner
template<>
class Inner<bool>

In general the reference must include a template parameter list for each template argument list. The full specialisation above can therefore be referenced with template\<> Outer\<int> (template<> Outer<int>) and template\<> template\<> Outer\<int>::Inner\<bool> (template<> template<> Outer<int>::Inner<bool>). As a shorthand the empty template parameter list can be omitted, e.g., Outer\<int> (Outer<int>) and Outer\<int>::Inner\<bool> (Outer<int>::Inner<bool>).

Partial Template Specialisations

Assume the following declaration.

template<typename T>
class Outer<T*>

References to partial specialisations must always include the template parameter lists, e.g., template\<typename T> Outer\<T*> (template<typename T> Outer<T*>). Currently the lookup only succeed if the template parameter identifiers are equal strings.

設定値

See C++ ドメインのオプション.