Difference between revisions of "cpp/ranges/contiguous range"
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{{ddcl|header = ranges|since=c++20|1= | {{ddcl|header = ranges|since=c++20|1= | ||
template< class T > | template< class T > | ||
| − | + | concept contiguous_range = | |
ranges::random_access_range<T> && | ranges::random_access_range<T> && | ||
std::contiguous_iterator<ranges::iterator_t<T>> && | std::contiguous_iterator<ranges::iterator_t<T>> && | ||
requires(T& t) { | requires(T& t) { | ||
| − | + | { ranges::data(t) } -> | |
| − | + | std::same_as<std::add_pointer_t<ranges::range_reference_t<T>>>; | |
}; | }; | ||
}} | }} | ||
| − | The {{ | + | The {{tt|contiguous_range}} concept is a refinement of {{lconcept|range}} for which {{lc|ranges::begin}} returns a model of {{lconcept|contiguous_iterator}} and the customization point {{lc|ranges::data}} is usable. |
===Semantic requirements=== | ===Semantic requirements=== | ||
| − | {{tt|T}} models {{ | + | {{tt|T}} models {{tt|contiguous_range}} only if given an expression {{tt|e}} such that {{c|decltype((e))}} is {{c|T&}}, {{c|1=std::to_address(ranges::begin(e)) == ranges::data(e)}}. |
===Example=== | ===Example=== | ||
| Line 29: | Line 29: | ||
#include <vector> | #include <vector> | ||
| − | template<typename T> concept CR = std::ranges::contiguous_range<T>; | + | template<typename T> |
| + | concept CR = std::ranges::contiguous_range<T>; | ||
int main() | int main() | ||
Revision as of 14:03, 21 June 2024
| Defined in header <ranges>
|
||
| template< class T > concept contiguous_range = |
(since C++20) | |
The contiguous_range concept is a refinement of range for which ranges::begin returns a model of contiguous_iterator and the customization point ranges::data is usable.
Semantic requirements
T models contiguous_range only if given an expression e such that decltype((e)) is T&, std::to_address(ranges::begin(e)) == ranges::data(e).
Example
Run this code
#include <array> #include <deque> #include <list> #include <ranges> #include <set> #include <valarray> #include <vector> template<typename T> concept CR = std::ranges::contiguous_range<T>; int main() { int a[4]; static_assert( CR<std::vector<int>> and not CR<std::vector<bool>> and not CR<std::deque<int>> and CR<std::valarray<int>> and CR<decltype(a)> and not CR<std::list<int>> and not CR<std::set<int>> and CR<std::array<std::list<int>,42>> ); }
See also
| (C++20) |
specifies that a range knows its size in constant time (concept) |
| (C++20) |
specifies a range whose iterator type satisfies random_access_iterator (concept) |
