Difference between revisions of "cpp/container/inplace vector"

Revision as of 22:37, 7 August 2024

Defined in header `<inplace_vector>`
template< class T, std::size_t N > struct inplace_vector;		(since C++26)

inplace_vector is a dynamically-resizable array with contiguous inplace storage (that is, the elements of type T are stored within the object itself) and with fixed at compile-time capacity N.

inplace_vector is useful in environments where dynamic memory allocations are undesired.

Member type	Definition
`value_type`	`T`[edit]
`size_type`	std::size_t[edit]
`difference_type`	std::ptrdiff_t[edit]
`reference`	value_type&[edit]
`const_reference`	const value_type&[edit]
`pointer`	value_type*[edit]
`const_pointer`	const value_type*[edit]
`iterator`	implementation-defined LegacyRandomAccessIterator and `random_access_iterator` to `value_type`[edit]
`const_iterator`	implementation-defined LegacyRandomAccessIterator and `random_access_iterator` to const value_type[edit]
`reverse_iterator`	std::reverse_iterator<iterator>[edit]
`const_reverse_iterator`	std::reverse_iterator<const_iterator>[edit]

Member functions

(constructor)	constructs the `inplace_vector` (public member function) [edit]
(destructor)	destructs the `inplace_vector` (public member function) [edit]
operator=	assigns values to the container (public member function) [edit]
assign	assigns values to the container (public member function) [edit]
assign_range	assigns a range of values to the container (public member function) [edit]
Element access
at	access specified element with bounds checking (public member function) [edit]
operator[]	access specified element (public member function) [edit]
front	access the first element (public member function) [edit]
back	access the last element (public member function) [edit]
data	direct access to the underlying contiguous storage (public member function) [edit]
Iterators
begincbegin	returns an iterator to the beginning (public member function) [edit]
endcend	returns an iterator to the end (public member function) [edit]
rbegincrbegin	returns a reverse iterator to the beginning (public member function) [edit]
rendcrend	returns a reverse iterator to the end (public member function) [edit]
Size and capacity
empty	checks whether the container is empty (public member function) [edit]
size	returns the number of elements (public member function) [edit]
max_size [static]	returns the maximum possible number of elements (public static member function) [edit]
capacity [static]	returns the number of elements that can be held in currently allocated storage (public static member function) [edit]
resize	changes the number of elements stored (public member function) [edit]
reserve [static]	reserves storage (public static member function) [edit]
shrink_to_fit [static]	reduces memory usage by freeing unused memory (public static member function) [edit]
Modifiers
insert	inserts elements (public member function) [edit]
insert_range	inserts a range of elements (public member function) [edit]
emplace	constructs element in-place (public member function) [edit]
emplace_back	constructs an element in-place at the end (public member function) [edit]
try_emplace_back	tries to construct an element in-place at the end (public member function) [edit]
unchecked_emplace_back	unconditionally constructs an element in-place at the end (public member function) [edit]
push_back	adds an element to the end (public member function) [edit]
try_push_back	tries to add an element to the end (public member function) [edit]
unchecked_push_back	unconditionally adds an element to the end (public member function) [edit]
pop_back	removes the last element (public member function) [edit]
append_range	adds a range of elements to the end (public member function) [edit]
try_append_range	tries to add a range of elements to the end (public member function) [edit]
resize	changes the number of elements stored (public member function) [edit]
clear	clears the contents (public member function) [edit]
erase	erases elements (public member function) [edit]
swap	swaps the contents (public member function) [edit]

Non-member functions

std::swap(std::inplace_vector) (C++26)	specializes the std::swap algorithm (function template) [edit]
erase(std::inplace_vector)erase_if(std::inplace_vector) (C++26)	erases all elements satisfying specific criteria (function template) [edit]
operator==operator<=> (C++26)	lexicographically compares the values of two `inplace_vector`s (function template) [edit]

Notes

Feature-test macro	Value	Std	Feature
`__cpp_lib_inplace_vector`	202406L	(C++26)	`std::inplace_vector`: dynamically-resizable vector with fixed capacity inplace storage

Example

External links

	Boost.Container: `static_vector` implements inplace vector as a standalone type with its own guarantees.
	EASTL: `fixed_vector` implements inplace vector via an extra template parameter.
	Folly: `small_vector` also implements inplace vector via an extra template parameter.
	Compiler Explorer — A reference implementation of P0843R14 (`std::inplace_vector`).

@@ Line 7: / Line 7: @@
 > struct inplace_vector;
 }}
+{{tt|inplace_vector}} is a dynamically-resizable array with contiguous inplace storage (that is, the elements of type {{tt|T}} are stored within the object itself) and with fixed at compile-time capacity {{tt|N}}.
+{{tt|inplace_vector}} is useful in environments where dynamic memory allocations are undesired.
 <!--DONE-->
@@ Line 35: / Line 39: @@
 {{par begin}}
 {{par|T|element type.<!--Must be a complete object type that is not an abstract class type.--> Must be {{named req|MoveConstructible}} and {{named req|MoveAssignable}}.}}
-{{par|N|the maximum number of elements in the {{tt|inplace_vector}} (might be {{c|0}}).}}
+{{par|N|capacity, i.e. the maximum number of elements in the {{tt|inplace_vector}} (might be {{c|0}}).}}
 {{par end}}
 {{todo|Complete the descriptions of template parameters.}}
@@ Line 138: / Line 142: @@
 {{dsc inc|cpp/container/dsc deque}}
 {{dsc end}}
+===External links===
+{{elink begin}}
+{{elink|[http://www.boost.org/doc/libs/1_59_0/doc/html/boost/container/static_vector.html Boost.Container: {{tt|static_vector}}] implements inplace vector as a standalone type with its own guarantees.}}
+{{elink|[https://github.com/questor/eastl/blob/master/fixed_vector.h#L71 EASTL: {{tt|fixed_vector}}] implements inplace vector via an extra template parameter.}}
+{{elink|[https://github.com/facebook/folly/blob/master/folly/docs/small_vector.md Folly: {{tt|small_vector}}] also implements inplace vector via an extra template parameter.}}
+{{elink|[https://godbolt.org/z/5P78aG5xE Compiler Explorer] &mdash; A reference implementation of {{stddoc|P0843R14}} ({{tt|std::inplace_vector}}).}}
+{{elink|}}
+{{elink end}}
 {{langlinks|de|es|fr|it|ja|pl|pt|ru|zh}}

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vector	dynamic contiguous array (class template) [edit]
array (C++11)	fixed-sized inplace contiguous array (class template) [edit]
deque	double-ended queue (class template) [edit]

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Difference between revisions of "cpp/container/inplace vector"

Revision as of 22:37, 7 August 2024

Contents

Iterator invalidation

Template parameters

Member types

Member functions

Element access

Iterators

Size and capacity

Modifiers

Non-member functions

Notes

Example

See also

External links

Navigation

Toolbox

T	-	element type. Must be MoveConstructible and MoveAssignable.
N	-	capacity, i.e. the maximum number of elements in the `inplace_vector` (might be 0).