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* 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>
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| title |
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| variant (legacy) |
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Header: variant.h
Similar to: std::variant
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Deprecated for C++11 and above.
This version is automatically selected if either the compiler does not support C++11, or ETL_USE_LEGACY_VARIANT is defined.
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A class that can contain one a several specified types in a type safe manner.
Supports up to eight types.
Supplies a nested reader visitor class that allows type safe access via sets of overloaded virtual read functions for each type.
Accepts etl::visit since 20.28.0.
If ETL_USE_LEGACY_VARIANT is defined then etl::variant is in the etl namespace.
If ETL_USE_LEGACY_VARIANT is not defined then etl::variant is in the etl::legacy namespace.
Since: 20.30.0.
Constructors
variant()
Description
Default constructor.
template <typename T>
variant(T value)
Description
Construct from value.
A static assert will occur if T is not a supported type.
Operations
template <typename T>
variant& operator =(typename parameter_type<T>::type value)
Description
Assigns a value.
A static assert occurs if the type T is not supported.
If C++11 is not supported
template <typename T, typename TP1>
T& emplace(const TP1& value1)
template <typename T, typename TP1, typename TP2>
T& emplace(const TP1& value1, const TP2& value2)
template <typename T, typename TP1, typename TP2, typename TP3>
T& emplace(const TP1& value1, const TP2& value2, const TP3& value3)
template <typename T, typename TP1, typename TP2, typename TP3, typename TP4>
T& emplace(const TP1& value1, const TP2& value2, const TP3& value3, const TP4& value4)
Description
Construct a T from multiple arguments.
If C++11 or greater is supported
template <typename T, typename... Args>
T& emplace(Args&&... args)
Description
Construct a Ts in-place using the supplied parameters.
void clear()
Description
Clears the variant of holding any type.
Access
template <typename T>
T& get()
Gets a value.
If T is a type not supported by the variant then a static assert occurs.
If T is a type that is not the type currently stored then a variant_incorrect_type_exception() error is raised.
If asserts or exceptions are not enabled then undefined behaviour occurs.
const template <typename T>
T& get() const
Gets a value.
If T is a type not supported by the variant then a static assert occurs.
If T is a type that is not the type currently stored then a variant_incorrect_type_exception() error is raised.
If asserts or exceptions are not enabled then undefined behaviour occurs.
T* upcast_ptr<T>()
const T* upcast_ptr<T>() const
For variant types that are polymorphic.
Up-casts the variant to type T*.
Types that cannot be up-cast will result in a nullptr return.
Since: 20.30.0
T& upcast<T>()
const T& upcast<T>() const
For variant types that are polymorphic.
Up-casts the variant to type T.
Types that cannot be up-cast will result in a runtime error etl::variant_not_a_base.
Since: 20.30.0
bool is_base_of<T>() const
Tests if the type T is a base of the current variant type.
Since: 20.30.0
call(reader& r)
Calls the appropriate overloaded r.read() function with the value.
template <typename T>
variant& operator =(typename parameter_type<T>::type value)
Assigns a value.
A static assert occurs if the type T is not supported.
Any value stored in the variant can be implicitly cast to its current type.
If the implicit cast is to a type not supported by the variant then a static assert occurs.
If the implicit cast is to a type that is not the type currently stored then a etl::variant_incorrect_type_exception error is raised.
Tests
template <typename T>
static bool is_supported_type()
Returns true if T is supported by the variant, otherwise false.
bool is_same_type(const variant& other) const
Returns true if the variant holds the same type as the other, otherwise false.
bool is_valid() const
Returns true if the variant holds a valid value, otherwise false.
template <typename T>
bool is_type() const
Returns true if T is the type currently stored in the variant, otherwise false.
Visitation
For STL style etl::visit
20.28.0
The ETL implements an STL style visit function.