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Defined in header <ranges> | ||
template< std::input_or_output_iterator I, | (1) | (since C++20) |
Helper concepts | ||
template<class From,class To> concept/*uses-nonqualification-pointer-conversion*/= | (2) | (exposition only*) |
template<class From,class To> concept/*convertible-to-non-slicing*/=/* see description */; | (3) | (exposition only*) |
subrange class template combines together an iterator and a sentinel into a singleview. It modelssized_range whenever the final template parameter issubrange_kind::sized (which happens whenstd::sized_sentinel_for<S, I> is satisfied or when size is passed explicitly as a constructor argument).From is convertible toTo withoutqualification conversions. Equivalent to:template<class From,class To>concept/*uses-nonqualification-pointer-conversion*/=std::is_pointer_v<From>&&std::is_pointer_v<To>&&!std::convertible_to<std::remove_pointer_t<From>(*)[],std::remove_pointer_t<To>(*)[]>;
From is convertible toTo without derived-to-base conversion:template<class From,class To>concept/*convertible-to-non-slicing*/=std::convertible_to<From, To>&&!/*uses-nonqualification-pointer-conversion*/<std::decay_t<From>,std::decay_t<To>>;
Contents |
| Member | Definition |
constexprboolStoreSize[static] | K== ranges::subrange_kind::sized&& !std::sized_sentinel_for<S, I>(exposition-only static member constant*) |
Ibegin_ | an iterator to the beginning of the subrange (exposition-only member object*) |
Send_ | a sentinel denoting the end of the subrange (exposition-only member object*) |
make-unsigned-like-t <std::iter_difference_t<I>>size_(present only if StoreSize istrue) | the size of the subrange (exposition-only member object*) |
creates a newsubrange(public member function) | |
converts thesubrange to apair-like type(public member function)[edit] | |
Observers | |
| obtains the iterator (public member function)[edit] | |
| obtains the sentinel (public member function)[edit] | |
checks whether thesubrange is empty(public member function)[edit] | |
obtains the size of thesubrange(public member function)[edit] | |
Iterator operations | |
| advances the iterator by given distance (public member function)[edit] | |
obtains a copy of thesubrange with its iterator decremented by a given distance(public member function)[edit] | |
obtains a copy of thesubrange with its iterator advanced by a given distance(public member function)[edit] | |
Inherited fromstd::ranges::view_interface | |
(C++23) | returns a constant iterator to the beginning of the range (public member function of std::ranges::view_interface<D>)[edit] |
(C++23) | returns a sentinel for the constant iterator of the range (public member function of std::ranges::view_interface<D>)[edit] |
| returns whether the derived view is not empty, provided only ifranges::empty is applicable to it (public member function of std::ranges::view_interface<D>)[edit] | |
gets the address of derived view's data, provided only if its iterator type satisfiescontiguous_iterator(public member function of std::ranges::view_interface<D>)[edit] | |
returns the first element in the derived view, provided if it satisfiesforward_range(public member function of std::ranges::view_interface<D>)[edit] | |
returns the last element in the derived view, provided only if it satisfiesbidirectional_range andcommon_range(public member function of std::ranges::view_interface<D>)[edit] | |
returns thenth element in the derived view, provided only if it satisfiesrandom_access_range(public member function of std::ranges::view_interface<D>)[edit] | |
(C++20) | obtains iterator or sentinel from astd::ranges::subrange (function template)[edit] |
(C++20) | specifies whether astd::ranges::subrange modelsstd::ranges::sized_range (enum)[edit] |
| obtains the size of astd::ranges::subrange (class template specialization)[edit] | |
| obtains the type of the iterator or the sentinel of astd::ranges::subrange (class template specialization)[edit] |
template<class I,class S,ranges::subrange_kind K> constexprboolranges::enable_borrowed_range<ranges::subrange<I, S, K>>=true; | (since C++20) | |
This specialization ofranges::enable_borrowed_range makessubrange satisfyborrowed_range.
#include <map>#include <print>#include <ranges> void make_uppercase(char& v){ v+='A'-'a';} void uppercase_transform(std::multimap<int,char>& m,int k){auto[first, last]= m.equal_range(k);for(auto&[_, v]: std::ranges::subrange(first, last)) make_uppercase(v);} int main(){std::multimap<int,char> mm{{4,'a'},{3,'-'},{4,'b'},{5,'-'},{4,'c'}};std::println("Before: {}", mm); uppercase_transform(mm,4);std::println("After: {}", mm);}
Output:
Before: {3: '-', 4: 'a', 4: 'b', 4: 'c', 5: '-'}After: {3: '-', 4: 'A', 4: 'B', 4: 'C', 5: '-'}The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 3470 | C++20 | convertible-to-non-slicing might reject qualification conversions | always accepts them |
(C++20) | helper class template for defining aview, using thecuriously recurring template pattern(class template)[edit] |
Read/write all values of astd::multimap with a given key in C++20 — SO |
