Defined in header <concepts> | ||
|---|---|---|
inline namespace /* unspecified */ {
inline constexpr /* unspecified */ swap = /* unspecified */;
}
| (since C++20) (customization point object) | |
| Call signature | ||
template< class T, class U >
requires /* see below */
constexpr void swap(T&& t, U&& u) noexcept(/* see below */);
|
Exchanges the values referenced by t and u.
A call to ranges::swap is equivalent to:
(void)swap(std::forward<T>(t), std::forward<U>(u)), if that expression is valid, where the overload resolution is performed with the following candidates: template<class T> void swap(T&, T&) = delete; template<class T, std::size_t N> void swap(T(&)[N], T(&)[N]) = delete; swap found by argument-dependent lookup.t and u, the program is ill-formed; no diagnostic required.(void)ranges::swap_ranges(t, u), if T and U are lvalue references to array types of equal extent (but possibly different element types) and ranges::swap(*t, *u) is a valid expression;T and U are both V& for some type V that meets the syntactic requirements of MoveConstructible<V> and Assignable<V&, V>, exchanges the referenced values as if by V v{std::move(t)}; t = std::move(u); u = std::move(v);. If the semantic requirements of either concept are not satisfied, the program is ill-formed; no diagnostic required.ranges::swap is ill-formed.ranges::swap can be used in a constant expression if every function it calls (as specified above) can be so used.
The name ranges::swap denotes a customization point object, which is a function object of a literal Semiregular class type (denoted, for exposition purposes, as SwapT). All instances of SwapT are equal. Thus, ranges::swap can be copied freely and its copies can be used interchangeably.
Given a set of types Args..., if std::declval<Args>()... meet the requirements for arguments to ranges::swap above, SwapT will satisfy std::Invocable<const SwapT&, Args...>. Otherwise, no function call operator of SwapT participates in overload resolution.
noexcept specification: noexcept(noexcept((void)swap(std::forward<T>(t), std::forward<T>(u))))swap is found as described above.noexcept specification: noexcept(noexcept(ranges::swap(*t, *u)))noexcept specification: noexcept(std::is_nothrow_move_constructible_v<V> &&
std::is_nothrow_move_assignable_v<V>)|
(C++20) | specifies that a type can be swapped or that two types can be swapped with each other (concept) |
| swaps the values of two objects (function template) |
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