coffee/etl
1
0
Fork 0
mirror of https://github.com/ETLCPP/etl.git synced 2026-06-16 00:46:03 +08:00
Code Issues Packages Projects Releases Wiki Activity
etl/docs/containers/variadics/tuple.md
John Wellbelove 4a88884b39
Issue/add hugo support for documentation (#1449) 
* Add ranges

* Initial Hugo setup

* Work in progress

* Added selection for local or remote site

* Updated to 'light' theme

* Changed to using Hextra Hugo theme

* Changed to using Hextra Hugo theme

* Changed to Hextra Hugo theme

* Change to Hextra Hugo theme

* Updated Hugo setup.

* Updated Hugo setup.

# Conflicts:
#	docs/releases/_index.md

* Work in progress

* Added new fonts

Added new documentation

* Latest documentation updates

* Latest documentation updates

# Conflicts:
#	docs/containers/array.md
#	docs/containers/array_view.md
#	docs/containers/array_wrapper.md
#	docs/containers/bip_buffer_spsc_atomic.md
#	docs/containers/bitset.md
#	docs/containers/indirect_vector.md
#	docs/containers/vector.md
#	docs/getting-started/compilers.md

* Added bloom_filter markdown doc

* Added more documentation

Updated CSS for light and dark modes

* Fixed some menus

Added mode documentation files

* Updated CSS rules

Added badges to home page
Added uniqur_ptr + pool tutorial

* Fixed formatting on the home page markdown

Modified light amd dark code formatting

* Updated unique_ptr-with-pool

* Added container and shared message tutorials

* Updates to documentation

* Added const_multimap

* Updated source-formatting.md

* Added initial raw text files form Web site editor

* Innore coverage build directory

* Exported raw text documentation files from the web site editor

* Hugo updates

* Added Hugo intalation and markdown descriptions

* More addition to the documentation

* Added closure.md and updates to delegate.md

* Added format.md

* Added documentation for etl::delegate_observable, etl::function, Base64 codec

* Added io_port documentation

* Added basic_format_spec

* Added documentation for string_stream and string utilities.

* Added more documentation

Updated the documentation CSS

* Added documentation for clocks, day, duration

* Added more documentation for chrono classes

Updated callouts

* More chrono documentation

* Completed chrono documentation

* Maths functions documentation

* Completed maths documentation

* Completed maths documentation

* Completed maths documentation

* Completed maths documentation

* Added multiple documentation files

* Added iterator.md

* Added debug_count.md and versions.md

* Added debug_count.md and versions.md

* Added more documentation

* More documentation

* Added some design pattern documentation

Modified some of the layout files
Modified the About documentation

* Converted more documentation pages

Modified the site CSS

* Added more documentation

Moced some documentation files to new directories

* Added more documentation

Tweaks to CSS

* Added callback_timer_deferred_locked documentation

* Added callback_timer_locked documentation

* More documentation updates

* More documentation updates

* More documentation updates

* New documentation files.

Harmonised file name format

* New documentation files.

* Multiple document updates

* Multiple document updates

* Final conversion of web pages

* Updates before PR

* Updates before PR

* Updates before PR

# Conflicts:
#	docs/blog/_index.md

* Final pre PR updates

* Updates to message framework documentation

* Renamed directory

* Fix spelling

* Added author and date to blog files

Moved documentation files merged from development

* Fixed 'Description' typo

* Fix typos

# Conflicts:
#	docs/IO/io_port.md
#	docs/containers/sets/const-multiset.md
#	docs/containers/sets/const-set.md
#	docs/maths/correlation.md
#	docs/maths/gamma.md

* Renamed two files to lower case

* Minor renaming

* Added author and date

* Updated callout on bresenham_line.md

Added support for showing the ETL version on the documentation first page, by copying the version.txt file as a hugo asset.
Updated the Python 'update_release.py' to copy 'version.txt'

* Replace space in filename with hyphen.

Added more information to hugo-commands.md

* Replace space in filename with hyphen.

Added more information to hugo-commands.md

# Conflicts:
#	docs/getting-started/view-the-docs-locally/hugo-commands.md

* Added a link to pseudo_moving_average.md

* Updated title pages for groups

* Fixed missing 404 for non-existent pages

* Fixed coordinate variable names in the 'Calculating the intersection' example

---------

Co-authored-by: Roland Reichwein <Roland.Reichwein@bmw.de>
Co-authored-by: John Wellbelove <john.wellbelove@etlcpp.com>
Co-authored-by: John Wellbelove <john.wellbelove@etlcpp.co.uk>
2026-06-06 13:12:44 +01:00

854 lines
17 KiB
Markdown
Raw Blame History

---
title: "tuple"
---
{{< callout type="info">}}
Header: `tuple.h`
Similar to: `std::tuple`
{{< /callout >}}
C++11 and above.
A fixed-size collection of heterogeneous values.
```cpp
template <typename... TTypes>
class tuple
```
## Traits
```cpp
template <typename T>
struct is_tuple
```
Type trait to check if a type is an `etl::tuple`
## Types
```cpp
using value_type = THead; ///< The type contained by this tuple.
using this_type = tuple<THead, TTail...>; ///< The type of this tuple.
using base_type = tuple<TTail...>; ///< The type of the base tuple.
using type_list = etl::type_list<THead, TTail...>; ///< The type list for this tuple.
using index_sequence_type = etl::make_index_sequence< number_of_types< THead, TTail...>()>; ///< The index_sequence type for this tuple.
```
## Constants
```cpp
inline constexpr private_tuple::ignore_t ignore;
```
From: C++17
---
```cpp
static constexpr private_tuple::ignore_t ignore;
```
Before: C++17
## Constructors
```cpp
ETL_CONSTEXPR14
tuple()
```
**Description**
Default constructor.
---
```cpp
ETL_CONSTEXPR14
tuple(const tuple<THead, TTail...>& other) = default;
```
**Description**
Copy constructor.
---
```cpp
ETL_CONSTEXPR14
tuple(tuple<THead, TTail...>&& other) = default;
```
**Description**
Move constructor.
---
```cpp
ETL_CONSTEXPR14
tuple& operator=(const tuple<THead, TTail...>& other) = default;
```
**Description**
Copy assignment.
---
```cpp
ETL_CONSTEXPR14
tuple& operator=(tuple<THead, TTail...>&& other) = default;
```
**Description**
Move assignment.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple(tuple<UTypes...>& other)
```
**Description**
Copy construct from lvalue reference tuple type.
Implicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
explicit tuple(tuple<UTypes...>& other)
```
**Description**
Copy construct from lvalue reference tuple type.
Explicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are **not** convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple(const tuple<UTypes...>& other)
```
**Description**
Copy construct from const lvalue reference tuple type.
Implicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
explicit tuple(const tuple<UTypes...>& other)
```
**Description**
Copy construct from const lvalue reference tuple type.
Explicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are **not** convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple(tuple<UHead, UTail...>&& other)
```
**Description**
Move construct from rvalue reference tuple type.
Implicit conversion
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
explicit tuple(tuple<UTypes...>&& other)
```
**Description**
Move construct from rvalue reference tuple type.
Explicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are **not** convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple(const tuple<UHead, UTail...>&& other)
```
**Description**
Move construct from const rvalue reference tuple type.
Implicit conversion
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
explicit tuple(const tuple<UTypes...>&& other)
```
**Description**
Move construct from const rvalue reference tuple type.
Explicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are **not** convertible to `TTypes`.
---
```cpp
ETL_CONSTEXPR14
tuple(const TTypes&... args)
```
**Description**
Construct from arguments.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple(UHead&& head, UTail&&... tail) ETL_NOEXCEPT
```
**Description**
Construct from arguments.
Implicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are not convertible to `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
explicit tuple(UHead&& head, UTail&&... tail) ETL_NOEXCEPT
```
**Description**
Construct from arguments.
Explicit conversion.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
- The number of `TTYpes` >= 1.
- `UTypes` are **not** convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
tuple(ETL_OR_STD::pair<U1, U2>& p) ETL_NOEXCEPT
```
**Description**
Construct from lvalue reference pair.
Implicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` and `U2` are convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
explicit tuple(ETL_OR_STD::pair<U1, U2>& p) ETL_NOEXCEPT
```
**Description**
Construct from lvalue reference pair.
Explicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` or `U2` are not convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
tuple(const ETL_OR_STD::pair<U1, U2>& p) ETL_NOEXCEPT
```
**Description**
Construct from const lvalue reference pair.
Implicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` and `U2` are convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
explicit tuple(const ETL_OR_STD::pair<U1, U2>& p) ETL_NOEXCEPT
```
**Description**
Construct from const lvalue reference pair.
Explicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` or `U2` are not convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
tuple(ETL_OR_STD::pair<U1, U2>&& p) ETL_NOEXCEPT
```
**Description**
Construct from rvalue reference pair.
Implicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` and `U2` are convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
explicit tuple(ETL_OR_STD::pair<U1, U2>&& p) ETL_NOEXCEPT
```
**Description**
Construct from rvalue reference pair.
Explicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` or `U2` are not convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
tuple(const ETL_OR_STD::pair<U1, U2>&& p) ETL_NOEXCEPT
```
**Description**
Construct from const rvalue reference pair.
Implicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` and `U2` are convertible to `TTypes`.
---
```cpp
template <typename U1, typename U2,
ETL_CONSTEXPR14
explicit tuple(const ETL_OR_STD::pair<U1, U2>&& p) ETL_NOEXCEPT
```
**Description**
Construct from const rvalue reference pair.
Explicit conversion.
Enabled if:-
- The number of `TTYpes` == 2.
- `U1` or `U2` are not convertible to `TTypes`.
## Assignment
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple& operator=(const tuple<UTypes...>& other)
```
**Description**
Copy assign from other tuple type.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
---
```cpp
template <typename... UTypes>
ETL_CONSTEXPR14
tuple& operator=(tuple<UTypes...>&& other)
```
**Description**
Move assign from other tuple type.
Enabled if:-
- The number of `UTypes` == number of `TTypes`.
---
```cpp
template <typename U1, typename U2>
ETL_CONSTEXPR14
tuple& operator=(ETL_OR_STD::pair<U1, U2>& p)
```
**Description**
Assign from lvalue pair tuple type.
Enabled if:-
- The number of `TTYpes` == 2.
---
```cpp
template <typename U1, typename U2>
ETL_CONSTEXPR14
tuple& operator=(const ETL_OR_STD::pair<U1, U2>& p)
```
**Description**
Assign from const lvalue pair tuple type.
Enabled if:-
- The number of `TTYpes` == 2.
---
```cpp
template <typename U1, typename U2>
ETL_CONSTEXPR14
tuple& operator=(ETL_OR_STD::pair<U1, U2>&& p)
```
**Description**
Assign from rvalue pair tuple type.
Enabled if:-
- The number of `TTYpes` == 2.
---
```cpp
template <typename U1, typename U2>
ETL_CONSTEXPR14
tuple& operator=(const ETL_OR_STD::pair<U1, U2>&& p)
```
**Description**
Assign from const rvalue pair tuple type.
Enabled if:-
- The number of `TTYpes` == 2.
## Other
```cpp
ETL_CONSTEXPR14
void swap(this_type& other)
```
**Description**
Swaps this tuple with another.
---
```cpp
ETL_NODISCARD
constexpr static size_t size()
```
**Description**
Returns the number of elements in the tuple.
## Template deduction guides
For C++17 and above.
```cpp
template <typename... TArgs>
tuple(TArgs... args) -> tuple<TArgs...>;
```
**Description**
From variadic arguments.
---
```cpp
template <typename T1, typename T2>
tuple(ETL_OR_STD::pair<T1, T2>) -> tuple<T1, T2>;
```
From a `pair`.
## Utility classes
```cpp
template <size_t Index, typename... TTypes>
struct tuple_element<Index, etl::tuple<TTypes...>>
```
**Description**
Gets the element type at `Index` in the tuple.
---
```cpp
template <typename... TTypes>
struct tuple_size<etl::tuple<TTypes...>>
```
**Description**
Gets the size of the tuple.
Derived from `etl::integral_constant<size_t, sizeof...(TTypes)>`.
---
```cpp
template <typename... TTypes>
struct common_type<etl::tuple<TTypes...>>
```
**Description**
Gets the common type of a tuple.
## Get an element
```cpp
template <size_t Index, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
etl::tuple_element_t<Index, etl::tuple<TTypes...>>& get(tuple<TTypes...>& t)
```
**Description**
Extracts the element at `Index` from the tuple.
`Index` must be an integer value in [`0`, `sizeof...(TTypes)`).
Returns a reference to the value.
---
```cpp
template <size_t Index, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
const etl::tuple_element_t<Index, etl::tuple<TTypes...>>& get(const tuple<TTypes...>& t)
```
**Description**
Extracts the element at `Index` from the tuple.
`Index` must be an integer value in [`0`, `sizeof...(TTypes)`).
Returns a const reference to the value.
---
```cpp
template <size_t Index, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
etl::tuple_element_t<Index, etl::tuple<TTypes...>>&& get(tuple<TTypes...>&& t)
```
**Description**
Extracts the element at `Index` from the tuple.
`Index` must be an integer value in [`0`, `sizeof...(TTypes)`).
Returns an rvalue reference.
---
```cpp
template <size_t Index, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
const etl::tuple_element_t<Index, etl::tuple<TTypes...>>&& get(const tuple<TTypes...>&& t)
```
**Description**
Extracts the element at `Index` from the tuple.
`Index` must be an integer value in [`0`, `sizeof...(TTypes)`).
Returns a const rvalue reference.
---
```cpp
template <typename T, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
T& get(tuple<TTypes...>& t)
```
**Description**
Extracts the element with type `T` from the tuple.
Static asserts if the tuple contains more than one `T`, or does not contain a `T` element.
Returns a reference to the value.
---
```cpp
template <typename T, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
const T& get(const tuple<TTypes...>& t)
```
**Description**
Extracts the element with type `T` from the tuple.
Static asserts if the tuple contains more than one `T`, or does not contain a `T` element.
Returns a const reference to the value.
---
```cpp
template <typename T, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
T&& get(tuple<TTypes...>&& t)
```
**Description**
Extracts the element with type `T` from the tuple.
Static asserts if the tuple contains more than one `T`, or does not contain a `T` element.
Returns an rvalue reference to the value.
---
```cpp
template <typename T, typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
const T&& get(const tuple<TTypes...>&& t)
```
**Description**
Extracts the element with type `T` from the tuple.
Static asserts if the tuple contain more than one `T`, or does not contain a `T` element.
Returns a const rvalue reference to the value.
---
```cpp
template <typename... TTypes>
ETL_CONSTEXPR
etl::tuple<TTypes&...> tie(TTypes&... args)
```
**Description**
Create a tuple of references to the provided arguments.
---
```cpp
template <typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
etl::tuple<etl::unwrap_ref_decay_t<TTypes>...> make_tuple(TTypes&&... args)
```
**Description**
Create a tuple from the provided arguments.
---
```cpp
template <typename TTuple, size_t... Indices>
ETL_NODISCARD
ETL_CONSTEXPR14
auto select_from_tuple(TTuple&& tuple,
etl::index_sequence<Indices...>)
-> etl::tuple<etl::tuple_element_t<Indices, etl::decay_t<TTuple>>...>
```
**Description**
Create a new tuple by selecting elements from another, given a run time index sequence.
Static asserts if the number of indices does not match the tuple size.
---
```cpp
template <size_t... Indices, typename TTuple>
ETL_NODISCARD
ETL_CONSTEXPR14
auto select_from_tuple(TTuple&& tuple)
-> etl::tuple<etl::tuple_element_t<Indices, etl::decay_t<TTuple>>...>
```
**Description**
Create a new tuple by selecting elements from another, given a template parameter index sequence.
Static asserts if the number of indices does not match the tuple size.
---
```cpp
template <typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
etl::tuple<TTypes&&...> forward_as_tuple(TTypes&&... args)
```
**Description**
Forward the arguments as a tuple.
---
```cpp
template <typename... Tuples>
ETL_NODISCARD
ETL_CONSTEXPR14
auto tuple_cat(Tuples&&... t) -> Tuple
```
**Description**
Concatenate the list of tuples.
---
## If using the STL
Converts an etl::tuple to a std::tuple.
```cpp
template <typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
auto to_std(const etl::tuple<TTypes...>& etl_tuple) -> std::tuple<etl::decay_t<TTypes>...>
```
**Description**
Converts a `const etl::tuple` to a `std::tuple`.
---
```cpp
template <typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
auto to_std(etl::tuple<TTypes...>&& etl_tuple) -> std::tuple<etl::decay_t<TTypes>...>
```
**Description**
Converts an `etl::tuple` to a `std::tuple`.
---
```cpp
template <typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
auto to_etl(const std::tuple<TTypes...>& std_tuple) -> etl::tuple<etl::decay_t<TTypes>...>
```
**Description**
Converts a `const std::tuple` to an `etl::tuple`.
---
```cpp
template <typename... TTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
auto to_etl(std::tuple<TTypes...>&& std_tuple) -> etl::tuple<etl::decay_t<TTypes>...>
```
**Description**
Converts a `std::tuple` to an `etl::tuple`.
## Comparisons
```cpp
template <typename... TTypes, typename... UTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
bool operator==(const etl::tuple<TTypes...>& lhs, const etl::tuple<UTypes...>& rhs)
```
**Description**
Equality operator.
---
```cpp
template <typename... TTypes, typename... UTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
bool operator!=(const etl::tuple<TTypes...>& lhs, const etl::tuple<UTypes...>& rhs)
```
**Description**
Inequality operator.
---
```cpp
template <typename... TTypes, typename... UTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
bool operator<(const etl::tuple<TTypes...>& lhs, const etl::tuple<UTypes...>& rhs)
```
**Description**
Less than operator.
---
```cpp
template <typename... TTypes, typename... UTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
bool operator<=(const etl::tuple<TTypes...>& lhs, const etl::tuple<UTypes...>& rhs)
```
**Description**
Less than or equals operator.
---
```cpp
template <typename... TTypes, typename... UTypes>
ETL_NODISCARD
ETL_CONSTEXPR14
bool operator>(const etl::tuple<TTypes...>& lhs, const etl::tuple<UTypes...>& rhs)
```
**Description**
Greater than operator.
---
```cpp
template <typename... TTypes, typename... UTypes>
ETL_NODISCARD ETL_CONSTEXPR14 bool operator>=(const etl::tuple<TTypes...>& lhs, const etl::tuple<UTypes...>& rhs)
```
**Description**
Greater than or equals operator.
## Swap
```cpp
template <typename... TTypes>
ETL_CONSTEXPR14
void swap(etl::tuple<TTypes...>& lhs, etl::tuple<TTypes...>& rhs)
```
**Description**
Swap two tuples.
## Helpers
```cpp
template <typename... TTypes>
struct tuple_from_type_list<etl::type_list<TTypes...>>
```
**Description**
Helper to turn `etl::type_list<TList>` into `etl::tuple<TList>`
---
```cpp
template <typename TTypeList>
using tuple_from_type_list_t = typename tuple_from_type_list<TTypeList>::type
```
## STL namespace definitions
```cpp
template <typename... Types>
struct tuple_size<etl::tuple<Types...>> : etl::integral_constant<size_t, sizeof...(Types)>
```
**Description**
Specialisation of `tuple_size` to allow the use of C++ structured bindings.
---
```cpp
template <size_t Index, typename... Types>
struct tuple_element<Index, etl::tuple<Types...>>
```
**Description**
Specialisation of `tuple_element` to allow the use of C++ structured bindings.
Reference in New Issue View Git Blame Copy Permalink