std::iter_value_t, std::iter_reference_t, std::iter_difference_t, std::iter_rvalue_reference_t, std::iter_common_reference_t
From cppreference.com
Defined in header <iterator>
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template< class T > concept /*dereferenceable*/ = /* see below */; // exposition only |
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template< class T > using iter_value_t = /* see below */; |
(1) | (since C++20) |
template< /*dereferenceable*/ T > using iter_reference_t = decltype(*std::declval<T&>()); |
(2) | (since C++20) |
template< class T > using iter_difference_t = /* see below */; |
(3) | (since C++20) |
template< /*dereferenceable*/ T> requires /* see below */ |
(4) | (since C++20) |
template< Readable T > using iter_common_reference_t = std::common_reference_t<std::iter_reference_t<T>, |
(5) | (since C++20) |
Compute the associated types of an iterator. The exposition-only concept dereferenceable
is satisfied if and only if the expression *std::declval<T&>()
is valid and has a referenceable type (in particular, not void).
1) Computes the value type of
T
. If std::iterator_traits<T> is not specialized, then std::iter_value_t<T> is std::readable_traits<T>::value_type. Otherwise, it is std::iterator_traits<T>::value_type.2) Computes the reference type of
T
.3) Computes the difference type of
T
. If std::iterator_traits<T> is not specialized, then std::iter_difference_t<T> is std::incrementable_traits<T>::difference_type. Otherwise, it is std::iterator_traits<T>::difference_type.4) Computes the rvalue reference type of
T
. The "see below" portion of the constraint on this alias template is satisfied if and only if the expression ranges::iter_move(std::declval<T&>()) is valid and has a referenceable type (in particular, not void).5) Computes the common reference type of
T
. This is the common reference type between its reference type and an lvalue reference to its value type.See also
specifies that a type is readable by applying operator * (concept) | |
specifies that a Semiregular type can be incremented with pre- and post-increment operators (concept) | |
computes the value type of a Readable type (class template) | |
computes the difference type of a WeaklyIncrementable type (class template) | |
provides uniform interface to the properties of an iterator (class template) |