std::experimental::ranges::exchange

 

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General utilities library

Utility components
swap	exchange
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invoke identity	equal_to not_equal_to	greater less	greater_equal less_equal
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is_swappable_withis_swappable	is_nothrow_swappable_withis_nothrow_swappable	common_reference common_type
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TagSpecifier TaggedType	tagged tag specifiers	tagged_pair make_tagged_pair	tagged_tuple make_tagged_tuple

 

Defined in header <experimental/ranges/utility>
template< MoveConstructible T, class U = T >     requires Assignable<T&, U> constexpr T exchange( T& obj, U&& new_val ) noexcept(/* see below */);		(ranges TS)

Replaces the value of obj with new_value and returns the old value of obj, as if by

T old_value = std::move(obj);
obj = std::forward<U>(new_value);
return old_value;

Parameters

obj	-	object whose value to replace
new_value	-	the value to assign to obj

Return value

The old value of obj.

Exceptions

noexcept specification:  

noexcept(std::is_nothrow_move_constructible<T>::value &&
         std::is_nothrow_assignable<T&, U>::value)

See also

exchange (C++14)

replaces the argument with a new value and returns its previous value (function template)