std::apply
From cppreference.com
| Defined in header
<tuple>
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| template <class F, class Tuple>
constexpr decltype(auto) apply(F&& f, Tuple&& t); |
(since C++17) | |
Invoke the Callable object f with a tuple of arguments.
Contents |
[edit] Parameters
| f | - | Callable object to be invoked
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| t | - | tuple whose elements to be used as arguments to f
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[edit] Return value
What returned by f.
[edit] Possible implementation
namespace detail { template <class F, class Tuple, std::size_t... I> constexpr decltype(auto) apply_impl( F&& f, Tuple&& t, std::index_sequence<I...> ) { return std::invoke(std::forward<F>(f), std::get<I>(std::forward<Tuple>(t))...); // Note: std::invoke is a C++17 feature } } // namespace detail template <class F, class Tuple> constexpr decltype(auto) apply(F&& f, Tuple&& t) { return detail::apply_impl(std::forward<F>(f), std::forward<Tuple>(t), std::make_index_sequence<std::tuple_size<std::decay_t<Tuple>>{}>{}); } |
[edit] Example
| This section is incomplete Reason: no example |
[edit] See also
creates a tuple object of the type defined by the argument types (function template) |
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creates a tuple of rvalue references (function template) |