std::vector<bool>
Defined in header <vector>
|
||
|
template
<
class Allocator |
||
std::
vector
<bool>
is a possibly space-efficient specialization of std::vector for the type bool
The manner in which
std::
vector
<bool>
is made space efficient (as well as whether it is optimized at all) is implementation defined. One potential optimization involves coalescing vector elements such that each element occupies a single bit instead of sizeof(bool)
std::
vector
<bool>
behaves similarly to std::vector
- Does not necessarily store its elements as a contiguous array.
- Exposes class
std::
vector<bool>::referenceas a method of accessing individual bits. In particular, objects of this class are returned by operator[] - Does not use std::allocator_traits::construct to construct bit values.
- Does not guarantee that different elements in the same container can be modified concurrently by different threads.
Member types
| Member type | Definition | ||||
value_type
|
bool | ||||
allocator_type
|
Allocator | ||||
size_type
|
implementation-defined | ||||
difference_type
|
implementation-defined | ||||
| proxy class representing a reference to a single bool (class) |
|||||
const_reference
|
bool | ||||
pointer
|
implementation-defined | ||||
const_pointer
|
implementation-defined | ||||
iterator
|
|
||||
const_iterator
|
|
||||
reverse_iterator
|
std::reverse_iterator<iterator> | ||||
const_reverse_iterator
|
std::reverse_iterator<const_iterator> |
Member functions
constructs the vector (public member function of std::vector<T,Allocator>) |
|
destructs the vector (public member function of std::vector<T,Allocator>) |
|
| assigns values to the container (public member function of std::vector<T,Allocator>) |
|
| assigns values to the container (public member function of std::vector<T,Allocator>) |
|
|
(C++23)
|
assigns a range of values to the container (public member function of std::vector<T,Allocator>) |
| returns the associated allocator (public member function of std::vector<T,Allocator>) |
|
Element access | |
| access specified element with bounds checking (public member function of std::vector<T,Allocator>) |
|
| access specified element (public member function of std::vector<T,Allocator>) |
|
| access the first element (public member function of std::vector<T,Allocator>) |
|
| access the last element (public member function of std::vector<T,Allocator>) |
|
Iterators | |
|
(C++11)
|
returns an iterator to the beginning (public member function of std::vector<T,Allocator>) |
|
(C++11)
|
returns an iterator to the end (public member function of std::vector<T,Allocator>) |
|
(C++11)
|
returns a reverse iterator to the beginning (public member function of std::vector<T,Allocator>) |
|
(C++11)
|
returns a reverse iterator to the end (public member function of std::vector<T,Allocator>) |
Capacity | |
| checks whether the container is empty (public member function of std::vector<T,Allocator>) |
|
| returns the number of elements (public member function of std::vector<T,Allocator>) |
|
| returns the maximum possible number of elements (public member function of std::vector<T,Allocator>) |
|
| reserves storage (public member function of std::vector<T,Allocator>) |
|
| returns the number of elements that can be held in currently allocated storage (public member function of std::vector<T,Allocator>) |
|
Modifiers | |
| clears the contents (public member function of std::vector<T,Allocator>) |
|
| inserts elements (public member function of std::vector<T,Allocator>) |
|
|
(C++23)
|
inserts a range of elements (public member function of std::vector<T,Allocator>) |
|
(C++23)
|
adds a range of elements to the end (public member function of std::vector<T,Allocator>) |
|
(C++11)
|
constructs element in-place (public member function of std::vector<T,Allocator>) |
| erases elements (public member function of std::vector<T,Allocator>) |
|
| adds an element to the end (public member function of std::vector<T,Allocator>) |
|
|
(C++11)
|
constructs an element in-place at the end (public member function of std::vector<T,Allocator>) |
| removes the last element (public member function of std::vector<T,Allocator>) |
|
| changes the number of elements stored (public member function of std::vector<T,Allocator>) |
|
| swaps the contents (public member function of std::vector<T,Allocator>) |
|
| |
| flips all the bits (public member function) |
|
|
[static]
|
swaps two std::vector<bool>::references (public static member function) |
Non-member functions
|
(removed in C++20)
(removed in C++20)
(removed in C++20)
(removed in C++20)
(removed in C++20)
(C++20)
|
lexicographically compares the values of two vectors (function template) |
| specializes the std::swap algorithm (function template) |
|
| erases all elements satisfying specific criteria (function template) |
Helper classes
|
(C++11)
|
hash support for std::
vector
<bool>
(class template specialization) |
Deduction guides (C++17)
Notes
If the size of the bitset is known at compile time, std::bitset may be used, which offers a richer set of member functions. In addition, boost::dynamic_bitset exists as an alternative to
std::
vector
<bool>
Since its representation may be optimized,
std::
vector
<bool>
does not necessarily meet all Container or SequenceContainer requirements. For example, because
std::
vector
<bool>::iterator
is implementation-defined, it may not satisfy the LegacyForwardIterator requirement. Use of algorithms such as std::search that require LegacyForwardIterators may result in either compile-time or run-time errors
The Boost.Container version of vector does not specialize for bool
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_containers_ranges |
202202L |
(C++23) | Ranges construction and insertion for containers |
Example
| This section is incomplete Reason: no example |
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2187 | C++11 | specializations for bool lacked emplace and emplace_back member functions
|
added |