sort
ranges
policy
C++17
Sorts the elements in the range [first,last) in non-descending order. The order of equal elements is not guaranteed to be …
Canonical referenceSection hub
Constrained algorithms (since C++20)
C++20 provides constrained versions of most algorithms in the namespace std::ranges. In these algorithms, a range can be specified as either an iterator-sentinel pair or as a single range argument, and projections and pointer-to-member callables are supported. Additionally, the return types of most algorithms have been changed to return all potentially useful information computed during the execution of the algorithm.
# Notes
Feature-test macro Value Std Feature __cpp_lib_algorithm_default_value_type 202403L (C++26) List-initialization for algorithms __cpp_lib_ranges 201911L (C++20) Ranges library and constrained algorithms __cpp_lib_ranges_contains 202207L (C++23) std::ranges::contains __cpp_lib_ranges_find_last 202207L (C++23) std::ranges::find_last __cpp_lib_ranges_fold 202207L (C++23) std::ranges fold algorithms __cpp_lib_ranges_iota 202202L (C++23) std::ranges::iota __cpp_lib_ranges_starts_ends_with 202106L (C++23) std::ranges::starts_with, std::ranges::ends_with __cpp_lib_shift 201806L (C++20) std::shift_left, std::shift_right 202202L (C++23) std::ranges::shift_left, std::ranges::shift_right __cpp_lib_ranges_generate_random 202403L (C++26) std::ranges::generate_random
# Defect reports
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| P3136R1 | C++20 | niebloids were allowed to be specified as special entitiesother than function objects | required to be specified as function objects |
This hub groups algorithms by task first, then points back to the canonical reference page. Ranges forms and execution-policy overloads stay attached to the same conceptual item.
Core algorithms
Start here for the small set of algorithms that anchor most day-to-day work: ordering, searching, transformation, partitioning, and numeric accumulation.
stable_sort
ranges
policy
C++17
Sorts the elements in the range [first,last) in non-descending order. The order of equivalent elements is guaranteed to be …
Canonical referencefind
ranges
policy
C++26
Returns an iterator to the first element in the range [first,last) that satisfies specific criteria (or last if there is no such …
Canonical referencelower_bound
ranges
C++26
Searches for the first element in the partitioned range [first,last) which is not ordered before value. # Declarations …
Canonical referencetransform
ranges
policy
C++17
std::transform applies the given function to the elements of the given input range(s), and stores the result in an output range …
Canonical referencecopy
ranges
policy
C++17
Copies the elements in the range, defined by [first,last), to another range beginning at d_first (copy destination range). # …
Canonical referenceremove
ranges
policy
C++26
Removes all elements satisfying specific criteria from the range [first,last) and returns a past-the-end iterator for the new end …
Canonical referencepartition
ranges
policy
C++17
Reorders the elements in the range [first,last) in such a way that all elements for which the predicate p returns true precede …
Canonical referencemerge
ranges
policy
C++17
Merges two sorted ranges [first1,last1) and [first2,last2) into one sorted range beginning at d_first. # Declarations template< …
Canonical referenceComputes the sum of the given value init and the elements in the range [first,last). # Declarations template< class InputIt, …
Canonical referenceFull index by task
Each panel groups one algorithm family and keeps the rows compact enough to scan like an index rather than a card wall.
Searching and lookup
- adjacent_findranges policy C++17
Searches the range [first,last) for two consecutive equal elements. # Declarations template< class …
- all_ofranges policy C++17
Checks if unary predicate p returns false for at least one element in the range [first,last). # Declarations …
- any_ofranges policy C++17
Checks if unary predicate p returns false for at least one element in the range [first,last). # Declarations …
- binary_searchranges C++26
Checks if an element equivalent to value appears within the partitioned range [first,last). # Declarations …
- countranges policy C++26
Returns the number of elements in the range [first,last) satisfying specific criteria. # Declarations …
- count_ifranges policy C++26
Returns the number of elements in the range [first,last) satisfying specific criteria. # Declarations …
- equal_rangeranges C++26
Returns a range containing all elements equivalent to value in the partitioned range [first,last). # …
- findranges policy C++26
Returns an iterator to the first element in the range [first,last) that satisfies specific criteria (or last …
- find_endranges policy C++17
Searches for the last occurrence of the sequence [s_first,s_last) in the range [first,last). # Declarations …
- find_first_ofranges policy C++17
Searches the range [first,last) for any of the elements in the range [s_first,s_last). # Declarations …
- find_ifranges policy C++26
Returns an iterator to the first element in the range [first,last) that satisfies specific criteria (or last …
- find_if_notranges policy C++26
Returns an iterator to the first element in the range [first,last) that satisfies specific criteria (or last …
- lower_boundranges C++26
Searches for the first element in the partitioned range [first,last) which is not ordered before value. # …
- none_ofranges policy C++17
Checks if unary predicate p returns false for at least one element in the range [first,last). # Declarations …
- containsranges C++26
Search-based algorithm that checks whether or not a given range contains a value with iterator-sentinel …
- contains_subrangeranges C++26
Search-based algorithm that checks whether or not a given range contains a value with iterator-sentinel …
- ends_withranges C++23
Checks whether the second range matches the suffix of the first range. # Declarations Call signature …
- find_lastranges C++26
Returns the last element in the range [first,last) that satisfies specific criteria: # Declarations Call …
- find_last_ifranges C++26
Returns the last element in the range [first,last) that satisfies specific criteria: # Declarations Call …
- find_last_if_notranges C++26
Returns the last element in the range [first,last) that satisfies specific criteria: # Declarations Call …
- starts_withranges C++23
Checks whether the second range matches the prefix of the first range. # Declarations Call signature …
- searchranges policy C++17
1-4) Searches for the first occurrence of the sequence of elements [s_first,s_last) in the range [first,last). …
- search_nranges policy C++26
Searches the range [first,last) for the first sequence of count identical elements, each equal to the given …
- upper_boundranges C++26
Searches for the first element in the partitioned range [first,last) which is ordered after value. # …
Partitioning
- is_partitionedranges policy C++17
Checks whether [first,last) is partitioned by the predicate p: all elements satisfy p appear before all …
- partitionranges policy C++17
Reorders the elements in the range [first,last) in such a way that all elements for which the predicate p …
- partition_copyranges policy C++17
Copies the elements from the range [first,last) to two different ranges depending on the value returned by …
- partition_pointranges C++20
Examines the partitioned range [first,last) and locates the end of the first partition, that is, the first …
- stable_partitionranges policy C++17
Reorders the elements in the range [first,last) in such a way that all elements for which the predicate p …
Set operations and merge
- includesranges policy C++17
Returns true if the sorted range [first2,last2) is a subsequence of the sorted range [first1,last1) (a …
- inplace_mergeranges policy C++17
Merges two consecutive sorted ranges [first,middle) and [middle,last) into one sorted range [first,last). # …
- mergeranges policy C++17
Merges two sorted ranges [first1,last1) and [first2,last2) into one sorted range beginning at d_first. # …
- set_differenceranges policy C++17
Copies the elements from the sorted range [first1,last1) which are not found in the sorted range …
- set_intersectionranges policy C++17
Constructs a sorted range beginning at d_first consisting of elements that are found in both sorted ranges …
- set_symmetric_differenceranges policy C++17
Computes symmetric difference of two sorted ranges: the elements that are found in either of the ranges, but …
- set_unionranges policy C++17
Constructs a sorted union beginning at d_first consisting of the set of elements present in one or both sorted …
Numeric and scans
Computes the sum of the given value init and the elements in the range [first,last). # Declarations …
- adjacent_differencepolicy C++17
Let T be the value type of decltype(first). # Declarations template< class InputIt, class OutputIt > …
- exclusive_scanpolicy C++17
Equivalent to exclusive_scan(first, last, d_first, init, std::plus<>(). # Declarations template< …
- inclusive_scanpolicy C++17
Equivalent to inclusive_scan(first, last, d_first, std::plus<>(). # Declarations template< class …
Computes inner product (i.e. sum of products) or performs ordered map/reduce operation on the range …
- iotaranges C++23
Fills the range [first,last) with sequentially increasing values, starting with value and repetitively …
If [first,last) is empty, does nothing. # Declarations template< class InputIt, class OutputIt > …
- fold_leftranges C++26
Left-folds the elements of given range, that is, returns the result of evaluation of the chain …
- fold_left_firstranges C++23
Left-folds the elements of given range, that is, returns the result of evaluation of the chain …
- fold_left_first_with_iterranges C++23
Left-folds the elements of given range, that is, returns the result of evaluation of the chain …
- fold_left_with_iterranges C++26
Left-folds the elements of given range, that is, returns the result of evaluation of the chain …
- fold_rightranges C++26
Right-folds the elements of given range, that is, returns the result of evaluation of the chain …
- fold_right_lastranges C++23
Right-folds the elements of given range, that is, returns the result of evaluation of the chain …
- reducepolicy C++17
Equivalent to reduce(first, last, typename std::iterator_traits::value_type{}). # Declarations template< …
- transform_exclusive_scanpolicy C++17
Computes the exclusive prefix sum using op. # Declarations template< class InputIt, class OutputIt, class …
- transform_inclusive_scanpolicy C++17
Computes the inclusive prefix sum using op. # Declarations template< class InputIt, class OutputIt, class …
- transform_reducepolicy C++17
Equivalent to transform_reduce(first1, last1, first2, init,std::plus<>(), std::multiplies<>()), …
Permutations
- is_permutationranges C++20
Checks whether [first1,last1) is a permutation of a range starting from first2: # Declarations template< …
- next_permutationranges C++20
Permutes the range [first,last) into the next permutation. Returns true if such a “next permutation” exists; …
- prev_permutationranges C++20
Transforms the range [first,last) into the previous permutation. Returns true if such permutation exists, …
- random_shuffleC++11
Reorders the elements in the given range [first,last) such that each possible permutation of those elements …
- sampleranges C++17
Selects n elements from the sequence [first,last) (without replacement) such that each possible sample has …
- shuffleranges C++20
Reorders the elements in the given range [first,last) such that each possible permutation of those elements …
Sorting and ordering
- is_sortedranges policy C++17
Checks if the elements in range [first,last) are sorted in non-descending order. # Declarations template< …
- is_sorted_untilranges policy C++17
Examines the range [first,last) and finds the largest range beginning at first in which the elements are …
- nth_elementranges policy C++17
nth_element rearranges elements in [first,last) such that after the rearrangement: # Declarations template< …
- partial_sortranges policy C++17
Rearranges elements such that the range [first,middle) contains the sorted middle − first smallest elements in …
- partial_sort_copyranges policy C++17
Sorts some of the elements in the range [first,last) in ascending order, storing the result in the range …
- sortranges policy C++17
Sorts the elements in the range [first,last) in non-descending order. The order of equal elements is not …
- stable_sortranges policy C++17
Sorts the elements in the range [first,last) in non-descending order. The order of equivalent elements is …
Modifying sequences
- copyranges policy C++17
Copies the elements in the range, defined by [first,last), to another range beginning at d_first (copy …
- copy_backwardranges C++20
Copies the elements from the range [first,last) to another range ending at d_last. The elements are copied in …
- copy_ifranges policy C++17
Copies the elements in the range, defined by [first,last), to another range beginning at d_first (copy …
- copy_nranges policy C++17
Copies exactly count values from the range beginning at first to the range beginning at result. Formally, for …
- fillranges policy C++26
Assigns the given value to all elements in the range [first,last). # Declarations template< class …
- fill_nranges policy C++26
Assigns the given value to the first count elements in the range beginning at first if count > 0. Does …
- for_eachranges policy C++17
Applies the given function object f to the result of dereferencing every iterator in the range [first,last). …
- for_each_nranges policy C++17
Applies the given function object f to the result of dereferencing every iterator in the range [first,first + …
- generateranges policy C++17
Assigns each element in range [first,last) a value generated by the given function object g. # Declarations …
- generate_nranges policy C++17
Assigns values, generated by given function object g, to the first count elements in the range beginning at …
Swaps the values of the elements the given iterators are pointing to. # Declarations template< class …
- moveranges policy C++17
Moves the elements in the range [first,last), to another range beginning at d_first, starting from first and …
- move_backwardranges C++20
Moves the elements from the range [first,last), to another range ending at d_last. The elements are moved in …
- generate_randomranges C++26
Attempts to generate random numbers with the generate_random member function of the random number generator or …
- removeranges policy C++26
Removes all elements satisfying specific criteria from the range [first,last) and returns a past-the-end …
- remove_copyranges policy C++26
Copies elements from the range [first,last), to another range beginning at d_first, omitting the elements …
- remove_copy_ifranges policy C++26
Copies elements from the range [first,last), to another range beginning at d_first, omitting the elements …
- remove_ifranges policy C++26
Removes all elements satisfying specific criteria from the range [first,last) and returns a past-the-end …
- replaceranges policy C++26
Replaces all elements in the range [first,last) with new_value if they satisfy specific criteria. # …
- replace_copyranges policy C++17
Copies the elements from the range [first,last) to another range beginning at d_first, while replacing all …
- replace_copy_ifranges policy C++17
Copies the elements from the range [first,last) to another range beginning at d_first, while replacing all …
- replace_ifranges policy C++26
Replaces all elements in the range [first,last) with new_value if they satisfy specific criteria. # …
- reverseranges policy C++17
Reverses the order of the elements in the range [first,last). # Declarations template< class BidirIt > …
- reverse_copyranges policy C++17
Given (\scriptsize N)N as std::distance(first, last). Copies the elements from the range [first,last) (source …
- rotateranges policy C++17
Performs a left rotation on a range of elements. # Declarations template< class ForwardIt > ForwardIt …
- rotate_copyranges policy C++17
Copies the elements from the range [first,last), to another range beginning at d_first in such a way, that …
- shift_leftranges policy C++20
Shifts the elements in the range [first,last) by n positions. # Declarations template< class ForwardIt > …
- shift_rightranges policy C++20
Shifts the elements in the range [first,last) by n positions. # Declarations template< class ForwardIt > …
Exchanges the given values. # Declarations template< class T > void swap( T& a, T& b ); …
- swap_rangesranges policy C++17
Exchanges elements between range [first1,last1) and another range of std::distance(first1, last1) elements …
- transformranges policy C++17
std::transform applies the given function to the elements of the given input range(s), and stores the result …
- uniqueranges policy C++17
Removes all except the first element from every consecutive group of equivalent elements from the range …
- unique_copyranges policy C++17
Copies the elements from the range [first,last), to another range beginning at d_first in such a way that …
Comparison and min/max
- clampranges C++17
If the value of v is within [lo,hi], returns v; otherwise returns the nearest boundary. # Declarations …
- equalranges policy C++17
Checks whether [first1,last1) and a range starting from first2 are equal: # Declarations template< class …
- lexicographical_compareranges policy C++17
Checks if the first range [first1,last1) is lexicographically less than the second range [first2,last2). # …
Lexicographically compares two ranges [first1,last1) and [first2,last2) using three-way comparison and …
- maxranges C++20
Returns the greater of the given values. # Declarations template< class T > const T& max( const …
- max_elementranges policy C++17
Finds the greatest element in the range [first,last). # Declarations template< class ForwardIt > …
- minranges C++20
Returns the smaller of the given values. # Declarations template< class T > const T& min( const …
- min_elementranges policy C++17
Finds the smallest element in the range [first,last). # Declarations template< class ForwardIt > …
- minmaxranges C++20
Returns the lowest and the greatest of the given values. # Declarations template< class T > …
- minmax_elementranges policy C++17
Finds the smallest and greatest element in the range [first,last). # Declarations template< class ForwardIt …
- mismatchranges policy C++17
Returns a pair of iterators to the first mismatching of elements from [first1,last1) and a range starting from …
Heap and priority structure
- is_heapranges policy C++17
Checks whether [first,last) is a heap. # Declarations template< class RandomIt > bool is_heap( RandomIt …
- is_heap_untilranges policy C++17
Examines the range [first,last) and finds the largest range beginning at first which is a heap. # Declarations …
- make_heapranges C++20
Constructs a heap in the range [first,last). # Declarations template< class RandomIt > void make_heap( …
- pop_heapranges C++20
Swaps the value in the position first and the value in the position last - 1 and makes the subrange …
- push_heapranges C++20
Inserts the element at the position last - 1 into the heap [first,last - 1). The heap after the insertion will …
- sort_heapranges C++20
Converts the heap [first,last) into a sorted range. The heap property is no longer maintained. # Declarations …
C compatibility
Finds an element equal to element pointed to by key in an array pointed to by ptr. The array contains count …
Sorts the given array pointed to by ptr in ascending order. The array contains count elements of size bytes. …