cppdraft_translate/cppdraft/utility/exchange.md

[utility.exchange]

22 General utilities library [utilities]

22.2 Utility components [utility]

22.2.3 exchange [utility.exchange]

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template<class T, class U = T> constexpr T exchange(T& obj, U&& new_val) noexcept(see below);

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Effects: Equivalent to:T old_val = std::move(obj); obj = std::forward(new_val);return old_val;

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Remarks: The exception specification is equivalent to:is_nothrow_move_constructible_v && is_nothrow_assignable_v<T&, U>