Constrained algorithms (since C++20)

 

C++

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Freestanding and hosted

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Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Execution support library (C++26)

Technical specifications

Symbols index

External libraries

 

Algorithm library

Constrained algorithms and algorithms on ranges (C++20)
Constrained algorithms, e.g. ranges::copy, ranges::sort, ...
Execution policies (C++17)
is_execution_policy (C++17)   execution::seqexecution::parexecution::par_unseqexecution::unseq (C++17)    (C++17)(C++17)(C++20)	execution::sequenced_policyexecution::parallel_policyexecution::parallel_unsequenced_policyexecution::parallel_unsequenced (C++17)(C++17)(C++17)(C++20)
Non-modifying sequence operations Batch operations for_each for_each_n (C++17) Search operations all_ofany_ofnone_of (C++11)                (C++11)(C++11) countcount_if mismatch equal findfind_iffind_if_not (C++11) find_end find_first_of adjacent_find search search_n Modifying sequence operations Copy operations copycopy_if (C++11) copy_backward copy_n (C++11) move (C++11) move_backward (C++11) Swap operations swap iter_swap swap_ranges Transformation operations replacereplace_if transform replace_copyreplace_copy_if Generation operations fill fill_n generate generate_n Removing operations removeremove_if unique remove_copyremove_copy_if unique_copy Order-changing operations reverse reverse_copy rotate rotate_copy random_shuffleshuffle (until C++17)(C++11) shift_leftshift_right (C++20)(C++20) Sampling operations sample (C++17)	Sorting and related operations Partitioning operations partition partition_copy (C++11)   stable_partition is_partitioned (C++11) partition_point (C++11) Sorting operations sort stable_sort partial_sort partial_sort_copy is_sorted (C++11) is_sorted_until (C++11) nth_element Binary search operations (on partitioned ranges) lower_bound upper_bound equal_range binary_search Set operations (on sorted ranges) includes set_union set_intersection set_difference set_symmetric_difference Merge operations (on sorted ranges) merge inplace_merge Heap operations push_heap pop_heap make_heap sort_heap is_heap (C++11) is_heap_until (C++11) Minimum/maximum operations max min minmax (C++11) clamp (C++17) max_element min_element minmax_element (C++11) Lexicographical comparison operations lexicographical_compare lexicographical_compare_three_way (C++20) Permutation operations next_permutation prev_permutation is_permutation (C++11) C library qsort bsearch
Numeric operations
iota (C++11) inner_product adjacent_difference    accumulate reduce (C++17) transform_reduce (C++17)	partial_sum inclusive_scan (C++17)    exclusive_scan (C++17) transform_inclusive_scan (C++17) transform_exclusive_scan (C++17)
Operations on uninitialized memory
uninitialized_copy uninitialized_move (C++17)    uninitialized_fill uninitialized_copy_n (C++11) uninitialized_move_n (C++17) uninitialized_fill_n	destroy (C++17) destroy_n (C++17) destroy_at (C++17) construct_at (C++20)       uninitialized_default_construct (C++17) uninitialized_value_construct (C++17) uninitialized_default_construct_n (C++17) uninitialized_value_construct_n (C++17)

 

Constrained algorithms

All names in this menu belong to namespace std::ranges

Non-modifying sequence operations

all_ofany_ofnone_of for_each for_each_n    countcount_if adjacent_find mismatch equal lexicographical_compare    containscontains_subrange (C++23)(C++23) findfind_iffind_if_not find_lastfind_last_iffind_last_if_not (C++23)(C++23)(C++23)   find_end find_first_of search search_n starts_with (C++23) ends_with (C++23)

Modifying sequence operations

copycopy_if copy_n copy_backward    move move_backward shift_leftshift_right (C++23)(C++23)   fill fill_n generate generate_n    transform swap_ranges    shuffle sample removeremove_if replacereplace_if reverse rotate remove_copyremove_copy_if    unique replace_copyreplace_copy_if reverse_copy rotate_copy unique_copy

Partitioning operations

is_partitioned    partition_point    partition    partition_copy    stable_partition

Sorting operations

is_sorted is_sorted_until     sort stable_sort         partial_sort       nth_element partial_sort_copy

Binary search operations (on sorted ranges)

lower_bound         upper_bound         binary_search      equal_range

Set operations (on sorted ranges)

merge inplace_merge       set_difference set_intersection    set_union          includes set_symmetric_difference

Heap operations

is_heap is_heap_until       make_heap           sort_heap push_heap pop_heap

Minimum/maximum operations

max max_element         min min_element         minmax minmax_element     clamp

Permutation operations

is_permutation      next_permutation    prev_permutation

Fold operations

fold_left (C++23) fold_left_first (C++23)   fold_right (C++23) fold_right_last (C++23)   fold_left_with_iter (C++23) fold_left_first_with_iter (C++23)

Numeric operations iota (C++23)             Random number generation generate_random (C++26)

Operations on uninitialized storage

construct_at    destroy destroy_n destroy_at uninitialized_copy    uninitialized_move uninitialized_fill uninitialized_copy_n    uninitialized_move_n uninitialized_fill_n uninitialized_default_construct uninitialized_default_construct_n uninitialized_value_construct uninitialized_value_construct_n

Return types

in_fun_result in_in_result in_found_result    in_out_result in_in_out_result    in_out_out_result    min_max_result out_value_result (C++23) in_value_result (C++23)

 

C++20 provides constrained versions of most algorithms in the namespace std::ranges. In these algorithms, a range can be specified as either a [[cpp//Iterator|Iterator]]-[[cpp//Sentinel|Sentinel]] pair or as a single [[cpp//Range|Range]] argument, and projections and pointer-to-member callables are supported. Additionally, the return type of most algorithms have been changed to return all potentially useful information computed during the execution of the algorithm.

Algorithm concepts and utilities

The header <iterator> provides a set of concepts and related utility designed to ease constraining common algorithm operations.

Defined in header <iterator>
Defined in namespace std
Indirect callable concepts
indirectly_unary_invocableindirectly_regular_unary_invocable (C++20)(C++20)	specifies that a callable type can be invoked with the result of dereferencing an indirectly_readable type (concept)
indirect_unary_predicate (C++20)	specifies that a callable type, when invoked with the result of dereferencing an indirectly_readable type, satisfies predicate (concept)
indirect_relation	specifies that a callable type, when invoked with the result of dereferencing two [[cpp//readable|readable]] types, satisfies predicate (concept)
indirect_strict_weak_order (C++20)	specifies that a callable type, when invoked with the result of dereferencing two indirectly_readable types, satisfies strict_weak_order (concept)
Common algorithm requirements
indirectly_movable (C++20)	specifies that values may be moved from an indirectly_readable type to an indirectly_writable type (concept)
indirectly_movable_storable (C++20)	specifies that values may be moved from an indirectly_readable type to an indirectly_writable type and that the move may be performed via an intermediate object (concept)
indirectly_copyable (C++20)	specifies that values may be copied from an indirectly_readable type to an indirectly_writable type (concept)
indirectly_copyable_storable (C++20)	specifies that values may be copied from an indirectly_readable type to an indirectly_writable type and that the copy may be performed via an intermediate object (concept)
indirectly_swappable (C++20)	specifies that the values referenced by two indirectly_readable types can be swapped (concept)
indirectly_comparable (C++20)	specifies that the values referenced by two indirectly_readable types can be compared (concept)
permutable (C++20)	specifies the common requirements of algorithms that reorder elements in place (concept)
mergeable (C++20)	specifies the requirements of algorithms that merge sorted sequences into an output sequence by copying elements (concept)
sortable (C++20)	specifies the common requirements of algorithms that permute sequences into ordered sequences (concept)
Utilities
indirect_result_t (C++20)	computes the result of invoking a callable object on the result of dereferencing some set of indirectly_readable types (alias template)
projected (C++20)	helper template for specifying the constraints on algorithms that accept projections (class template)

Constrained algorithms

Defined in header <algorithm>
Defined in namespace std::ranges
Non-modifying sequence operations
ranges::all_ofranges::any_ofranges::none_of (C++20)(C++20)(C++20)	checks if a predicate is true for all, any or none of the elements in a range (niebloid)
ranges::for_each (C++20)	applies a function to a range of elements (niebloid)
ranges::countranges::count_if (C++20)(C++20)	returns the number of elements satisfying specific criteria (niebloid)
ranges::mismatch (C++20)	finds the first position where two ranges differ (niebloid)
ranges::equal (C++20)	determines if two sets of elements are the same (niebloid)
ranges::lexicographical_compare (C++20)	returns true if one range is lexicographically less than another (niebloid)
ranges::findranges::find_ifranges::find_if_not (C++20)(C++20)(C++20)	finds the first element satisfying specific criteria (niebloid)
ranges::find_end (C++20)	finds the last sequence of elements in a certain range (niebloid)
ranges::find_first_of (C++20)	searches for any one of a set of elements (niebloid)
ranges::adjacent_find (C++20)	finds the first two adjacent items that are equal (or satisfy a given predicate) (niebloid)
ranges::search (C++20)	searches for the first occurrence of a range of elements (niebloid)
ranges::search_n (C++20)	searches for the first occurrence of a number consecutive copies of an element in a range (niebloid)
Modifying sequence operations
ranges::copyranges::copy_if (C++20)(C++20)	copies a range of elements to a new location (niebloid)
ranges::copy_n (C++20)	copies a number of elements to a new location (niebloid)
ranges::copy_backward (C++20)	copies a range of elements in backwards order (niebloid)
ranges::move (C++20)	moves a range of elements to a new location (niebloid)
ranges::move_backward (C++20)	moves a range of elements to a new location in backwards order (niebloid)
ranges::fill (C++20)	assigns a range of elements a certain value (niebloid)
ranges::fill_n (C++20)	assigns a value to a number of elements (niebloid)
ranges::transform (C++20)	applies a function to a range of elements (niebloid)
ranges::generate (C++20)	saves the result of a function in a range (niebloid)
ranges::generate_n (C++20)	saves the result of N applications of a function (niebloid)
ranges::removeranges::remove_if (C++20)(C++20)	removes elements satisfying specific criteria (niebloid)
ranges::remove_copyranges::remove_copy_if (C++20)(C++20)	copies a range of elements omitting those that satisfy specific criteria (niebloid)
ranges::replaceranges::replace_if (C++20)(C++20)	replaces all values satisfying specific criteria with another value (niebloid)
ranges::replace_copyranges::replace_copy_if (C++20)(C++20)	copies a range, replacing elements satisfying specific criteria with another value (niebloid)
ranges::swap_ranges (C++20)	swaps two ranges of elements (niebloid)
ranges::reverse (C++20)	reverses the order of elements in a range (niebloid)
ranges::reverse_copy (C++20)	creates a copy of a range that is reversed (niebloid)
ranges::rotate (C++20)	rotates the order of elements in a range (niebloid)
ranges::rotate_copy (C++20)	copies and rotate a range of elements (niebloid)
ranges::shuffle (C++20)	randomly re-orders elements in a range (niebloid)
ranges::unique (C++20)	removes consecutive duplicate elements in a range (niebloid)
ranges::unique_copy (C++20)	creates a copy of some range of elements that contains no consecutive duplicates (niebloid)
Partitioning operations
ranges::is_partitioned (C++20)	determines if the range is partitioned by the given predicate (niebloid)
ranges::partition (C++20)	divides a range of elements into two groups (niebloid)
ranges::partition_copy (C++20)	copies a range dividing the elements into two groups (niebloid)
ranges::stable_partition (C++20)	divides elements into two groups while preserving their relative order (niebloid)
ranges::partition_point (C++20)	locates the partition point of a partitioned range (niebloid)
Sorting operations
ranges::is_sorted (C++20)	checks whether a range is sorted into ascending order (niebloid)
ranges::is_sorted_until (C++20)	finds the largest sorted subrange (niebloid)
ranges::sort (C++20)	sorts a range into ascending order (niebloid)
ranges::partial_sort (C++20)	sorts the first N elements of a range (niebloid)
ranges::partial_sort_copy (C++20)	copies and partially sorts a range of elements (niebloid)
ranges::stable_sort (C++20)	sorts a range of elements while preserving order between equal elements (niebloid)
ranges::nth_element (C++20)	partially sorts the given range making sure that it is partitioned by the given element (niebloid)
Binary search operations (on sorted ranges)
ranges::lower_bound (C++20)	returns an iterator to the first element not less than the given value (niebloid)
ranges::upper_bound (C++20)	returns an iterator to the first element greater than a certain value (niebloid)
ranges::binary_search (C++20)	determines if an element exists in a partially-ordered range (niebloid)
ranges::equal_range (C++20)	returns range of elements matching a specific key (niebloid)
Set operations (on sorted ranges)
ranges::merge (C++20)	merges two sorted ranges (niebloid)
ranges::inplace_merge (C++20)	merges two ordered ranges in-place (niebloid)
ranges::includes (C++20)	returns true if one sequence is a subsequence of another (niebloid)
ranges::set_difference (C++20)	computes the difference between two sets (niebloid)
ranges::set_intersection (C++20)	computes the intersection of two sets (niebloid)
ranges::set_symmetric_difference (C++20)	computes the symmetric difference between two sets (niebloid)
ranges::set_union (C++20)	computes the union of two sets (niebloid)
Heap operations
ranges::is_heap (C++20)	checks if the given range is a max heap (niebloid)
ranges::is_heap_until (C++20)	finds the largest subrange that is a max heap (niebloid)
ranges::make_heap (C++20)	creates a max heap out of a range of elements (niebloid)
ranges::push_heap (C++20)	adds an element to a max heap (niebloid)
ranges::pop_heap (C++20)	removes the largest element from a max heap (niebloid)
ranges::sort_heap (C++20)	turns a max heap into a range of elements sorted in ascending order (niebloid)
Minimum/maximum operations
ranges::max (C++20)	returns the greater of the given values (niebloid)
ranges::max_element (C++20)	returns the largest element in a range (niebloid)
ranges::min (C++20)	returns the smaller of the given values (niebloid)
ranges::min_element (C++20)	returns the smallest element in a range (niebloid)
ranges::minmax (C++20)	returns the smaller and larger of two elements (niebloid)
ranges::minmax_element (C++20)	returns the smallest and the largest elements in a range (niebloid)
Permutation operations
ranges::is_permutation (C++20)	determines if a sequence is a permutation of another sequence (niebloid)
ranges::next_permutation (C++20)	generates the next greater lexicographic permutation of a range of elements (niebloid)
ranges::prev_permutation (C++20)	generates the next smaller lexicographic permutation of a range of elements (niebloid)