4a88884b39
* 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>
8.6 KiB
| title |
|---|
| Utility |
{{< callout type="info">}}
Header: utility.h
{{< /callout >}}
Useful utility functions and classes.
pair
template <typename T1, typename T2>
struct pair
Description
A clone of std::pair
C++03
template <typename T1, typename T2>
pair<T1, T2> make_pair(T1 a, T2 b)
C++11 and above
template <typename T1, typename T2>
pair<T1, T2> make_pair(T1&& a, T2&& b)
Description
Returns a pair.
template <size_t Index, typename T1, typename T2>
struct tuple_element<Index, ETL_OR_STD::pair<T1, T2>>
Description
Specialisation for pair.
Gets the type in the pair at Index.
Static asserts if Index is not 0 or 1.
From: 20.40.1
template <typename T1, typename T2>
struct tuple_size<ETL_OR_STD::pair<T1, T2>>
Description
Specialisation for pair.
Gets the size of the pair, which is always 2.
Since:20.40.1
Template deduction guides
C++17 and above
template <typename T1, typename T2>
pair(T1, T2) ->pair<T1, T2>;
exchange
template <typename T, typename U = T>
T exchange(T& object, const U& new_value)
Description
Copies the new value to object and returns the old value.
Note: This is not an atomic operation.
add_const
template <typename T>
typename etl::add_const<T>::type& as_const(T& t)
Description
Returns a value of type T as a const T.
coordinate_2d
template <typename T>
struct coordinate_2d
Member types
T x;
T y;
in_place disambiguation tags.
struct in_place_t
inline constexpr in_place_t in_place{}; // C++17
template <typename T> struct in_place_type_t
template <typename T>
inline constexpr in_place_type_t<T> in_place_type{}; // C++17
template <size_t I> struct in_place_index_t
template <size_t I>
inline constexpr in_place_index_t<I> in_place_index{}; // C++17
declval
template <typename T>
typename etl::add_rvalue_reference<T>::type declval() ETL_NOEXCEPT;
C++11
functor
For C++11 and above.
From: 20.27.0
template <typename TReturn, typename... TParams>
class functor
Description
Wraps a free/global function in a functor.
constexpr functor(TReturn(*ptr_)(TParams...))
Constructs a functor from a function pointer.
constexpr TReturn operator()(TParams... args) const
Description
Function operator.
Calls the wrapped function with the forwarded parameters.
Example
void int Function(int i)
{
return i;
}
// Note that the functor deduces the template parameters.
constexpr etl::functor f(Function);
member_function_wrapper
For C++11 and above.
From: 20.27.0
template <typename TReturn, typename... TParams>
class member_function_wrapper<TReturn(TParams...)>
Description
Wraps a member function in a static member function.
template <typename T, T& Instance, TReturn(T::* Method)(TParams...)>
static constexpr TReturn function(TParams... params)
Description
The static function that calls the member function.
Example
class MyClass
{
public:
int MemberFunction(int i)
{
return 2 * i;
}
};
MyClass test;
constexpr int(*pf)(int)
= &etl::member_function_wrapper<int(int)>::function<MyClass, test, &MyClass::MemberFunction>;
// Call
int result = pf(1);
functor_wrapper
For C++11 and above.
From: 20.27.0
template <typename TReturn, typename... TParams>
class functor_wrapper<TReturn(TParams...)>
Description
Wraps a functor in a static member function.
template <typename TFunctor, TFunctor& Instance>
static constexpr TReturn function(TParams... params)
Description
The static function that calls the member function.
Example
class MyClass
{
public:
int operator()(int i)
{
return 2 * i;
}
};
MyClass test;
constexpr int(*pf)(int) = &etl::functor_wrapper<int(int)>::function<MyClass, test>;
// Call
int result = pf(1);
functor_as_static
For C++17 and above. 20.40.0
Wraps a functor with a static free function at compile time.
Creates a static member call that calls the specified functor.
template <auto& Instance>
struct functor_as_static
template <typename... TArgs>
static constexpr auto call(TArgs&&... args)
Description
Member static function that calls the functor
Example
struct Test
{
int operator()(int i)
{
return 2 * i;
}
};
Test test;
using fas_t = etl::functor_as_static<test>;
fas_t::call(1));
member_function_as_static
For C++17 and above.
From: 20.40.0
Wraps a member function with a static free function at compile time.
Creates a static member function that calls the specified member function.
template <auto Method, auto& Instance>
struct member_function_as_static
template <typename... TArgs>
static constexpr auto call(TArgs&&... args)
Description
Member static function that calls the member function.
Example
struct Test
{
int Function()(int i)
{
return 2 * i;
}
};
Test test;
using mfas_t = etl::functor_as_static<&Test::Function, test>;
mfas_t::call(1));
member_function_as_functor
For C++17 and above.
From: 20.40.0
Wraps a member function with a functor at compile time.
Creates a functor that calls the specified member function.
template <auto Method, auto& Instance>
class member_function_as_functor
template <typename... TArgs>
constexpr auto operator()(TArgs&&... args) const
Description
Calls the functor.
Example
struct Test
{
int Function()(int i)
{
return 2 * i;
}
};
constexpr etl::member_function_as_functor<&Test::Function, test> mfaf;
mfaf(1);
function_as_functor
For C++17 and above.
From: 20.40.0
Wraps a function with a functor at compile time.
Creates a functor that calls the specified free function.
template <auto Function>
class function_as_functor
constexpr auto operator()(TArgs&&... args) const
Description
Calls the functor.
Example
int Function()(int i)
{
return 2 * i;
}
constexpr etl::function_as_functor<Function> faf;
faf(1);
function_ptr_as_functor
For C++11 and above.
From: 20.40.0
Wraps a function pointer with a functor at run time.
Creates a functor that calls the specified free function.
template <typename TReturn, typename... TArgs>
class function_ptr_as_functor
constexpr function_ptr_as_functor(TReturn(*ptr_)(TArgs...))
Description
Construct from a function pointer.
constexpr TReturn operator()(TArgs... args) const
Description
Function operator.
Example
int Function()(int i)
{
return 2 * i;
}
using function_type = decltype(Function);
constexpr function_type* fptr = Function;
constexpr etl::function_ptr_as_functor<function_type> fpaf(fptr)
integer_sequence
From: 20.14.0
template <typename T, T... Integers>
class integer_sequence
index_sequence
From: 20.14.0
template <size_t... Indices>
using index_sequence = etl::integer_sequence<size_t, Indices...>;
template <size_t N>
make_index_sequence
select1st & select2nd
select1st
A functor object that takes a single argument, a pair, and returns the pair::first element.
select2nd
A functor object that takes a single argument, a pair, and returns the pair::second element.
size_of_type
From: 20.36.0
template <typename T>
ETL_CONSTEXPR size_t size_of_type()
Description
Returns the size of the type defined in T.
template <typename T>
ETL_CONSTEXPR size_t size_of_type(const T&)
Description
Returns the size of the type defined in T.
ETL_SIZE_OF_OBJECT_TYPE(Object, Type)
Description
Returns the size of Type defined in the declared type of Object.
C++11 and above.
From: 20.36.0
ETL_SIZE_OF_CLASS_TYPE(Class, Type)
Description
Returns the size of Type defined in Class.
From: 20.36.0
nontype_t
Since 20.43.0
Wraps a non-type template parameter as a type.
Defines a value associated with the template type.
If ETL_FORCE_CPP11_NONTYPE is defined then the C++14 and below variant is used.
C++14 and below
template <typename T, T Value>
struct nontype_t;
using FortyTwo = etl::nontype_t<int, 42>;
C++17 and above
template <auto Value>
struct nontype_t;
using FortyTwo = etl::nontype_t<42>