std::vector<bool, Alloc>::reference
class reference; |
||
The std::vector
<bool, Alloc> specializations define std::vector
<bool, Alloc>::reference as a publicly-accessible nested class. std::vector
<
bool, Alloc>
::
reference
proxies the behavior of references to a single bit in std::vector
<bool, Alloc>
The primary use of std::vector
<
bool, Alloc>
::
reference
is to provide an lvalue that can be returned from operator[]
Any reads or writes to a vector that happen via a std::vector
<
bool, Alloc>
::
reference
Member functions
(constructor) |
constructs the reference. There is no default constructor. The copy constructor is implicitly declared(until C++11)
defaulted(since C++11). There may be internal constructor that is accessible only to std::vector
<bool, Alloc> itself. (public member function) |
(destructor) |
destroys the reference (public member function) |
operator= |
assigns a bool to the referenced bit (public member function) |
operator bool |
returns the referenced bit (public member function) |
flip |
flips the referenced bit (public member function) |
std::vector<bool, Alloc>::reference::~reference
~reference(); |
(until C++20) | |
constexpr ~reference(); |
(since C++20) | |
Destroys the reference.
std::vector<bool, Alloc>::reference::operator=
| (1) | ||
|
reference& operator=( bool x );
|
(until C++11) | |
|
reference& operator=
(
bool x )
noexcept
;
|
(since C++11) (until C++20) |
|
|
constexpr reference& operator=
(
bool x )
noexcept
;
|
(since C++20) | |
| (2) | ||
|
reference& operator=
(
const reference& x )
;
|
(until C++11) | |
|
reference& operator=
(
const reference& x )
noexcept
;
|
(since C++11) (until C++20) |
|
|
constexpr reference& operator=
(
const reference& x )
noexcept
;
|
(since C++20) | |
|
constexpr
const reference& operator=
(
bool x )
const
noexcept
;
|
(3) | (since C++23) |
Assigns a value to the referenced bit.
Parameters
| x | - | value to assign |
Return value
*this
std::vector<bool, Alloc>::reference::operator bool
operator bool() const; |
(until C++11) | |
operator bool() const noexcept; |
(since C++11) (until C++20) |
|
|
constexpr operator bool
(
)
const
noexcept
;
|
(since C++20) | |
Returns the value of the referenced bit.
Parameters
(none)
Return value
The referenced bit.
std::vector<bool, Alloc>::reference::flip
void flip(); |
(until C++11) | |
void flip() noexcept; |
(since C++11) (until C++20) |
|
constexpr void flip() noexcept; |
(since C++20) | |
Inverts the referenced bit.
Parameters
(none)
Return value
(none)
Helper classes
std::formatter<std::vector<bool, Alloc>::reference>
|
template
<
class T, class CharT >
requires /*is-vector-bool-reference*/<T> |
(since C++23) | |
Specializes the std::formatter for std::vector
<bool, Alloc>::reference. The specialization uses
std::formatter
<
bool, CharT>
as its underlying formatter (denoted as underlying_) where the referenced bit is converted to bool
The exposition-only constant /*is-vector-bool-reference*/<T> is true if and only if T denotes the type std::vector
<bool, Alloc>::reference for some type Alloc and std::vector
<bool, Alloc> is not a program-defined specialization
Member functions
|
template
<
class ParseContext >
constexpr ParseContext:: iterator parse( ParseContext& ctx ) ; |
(1) | (since C++23) |
|
template
<
class FormatContext >
FormatContext:: iterator format( const T& r, FormatContext& ctx ) const ; |
(2) | (since C++23) |
underlying_
.parse(ctx);
underlying_
.format(r, ctx);
Example
| This section is incomplete Reason: no example |
See also
| access specified element (public member function of std::vector<T,Allocator>) |
|
|
[static] |
swaps two std::vector<bool>::references (public static member function) |
External links
"Effective Modern C++" by Scott Meyers (2015), Chapter 2, Item 6: "Use the explicitly typed initializer idiom when auto deduces undesired types." (p.43-46) — describes a possible misuse of the proxy class std::vector<bool>::reference
|