std::experimental::ranges::is_swappable_with, std::experimental::ranges::is_swappable, std::experimental::ranges::is_nothrow_swappable_with, std::experimental::ranges::
From cppreference.com
< cpp | experimental | ranges
Defined in header <experimental/ranges/type_traits>
|
||
|
template
<
class T, class U >
struct is_swappable_with; |
(1) | (ranges TS) |
|
template< class T >
struct is_swappable; |
(2) | (ranges TS) |
|
template
<
class T, class U >
struct is_nothrow_swappable_with; |
(3) | (ranges TS) |
|
template
<
class T >
struct is_nothrow_swappable; |
(4) | (ranges TS) |
1) If the expressions
ranges::swap
(
std::declval
<T>
(
), std::declval
<U>
(
)
)
and
ranges::swap
(
std::declval
<U>
(
), std::declval
<T>
(
)
)
are both well-formed when treated as an unevaluated operand, provides the member constant
value equal true. Otherwise, value is false. Access checks
2) If
T is not a referenceable type (i.e., possibly cv-qualified void or a function type with a cv-qualifier-seq or a ref-qualifier), provides a member constant value equal to false. Otherwise, provides a member constant value equal to
ranges::
is_swappable_with
<T&, T&
>
::
value
3) Same as (1), but evaluations of both expressions from (1) are known not to throw exceptions.
4) Same as (2), but uses is_nothrow_swappable_with.
T and U shall each be a complete type, (possibly cv-qualified) void
Helper variable templates
|
template
<
class T, class U >
constexpr bool is_swappable_with_v = is_swappable_with<T, U> :: value ; |
(1) | (ranges TS) |
|
template
<
class T >
constexpr bool is_swappable_v = is_swappable<T> :: value ; |
(2) | (ranges TS) |
|
template
<
class T, class U >
constexpr bool is_nothrow_swappable_with_v = is_nothrow_swappable_with<T, U> :: value ; |
(3) | (ranges TS) |
|
template
<
class T >
constexpr bool is_nothrow_swappable_v = is_nothrow_swappable<T> :: value ; |
(4) | (ranges TS) |
Inherited from std::integral_constant
Member constants
value [static] |
true if T is swappable with U, false otherwise (public static member constant) |
Member functions
operator bool |
converts the object to bool, returns value
(public member function) |
operator() (C++14) |
returns value (public member function) |
Member types
| Type | Definition |
value_type
|
bool |
type
|
std::integral_constant < bool, value> |
Notes
This trait does not check anything outside the immediate context of the swap expressions: if the use of T or U would trigger template specializations, generation of implicitly-defined special member functions etc, and those have errors, the actual swap may not compile even if ranges::is_swappable_with<T,U>::value compiles and evaluates to true
Example
| This section is incomplete Reason: no example |
See also
| specifies that a type can be swapped or that two types can be swapped with each other (concept) |
|
|
(C++17)
(C++17)
(C++17)
(C++17)
|
checks if objects of a type can be swapped with objects of same or different type (class template) |