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 a Iterator-Sentinel pair or as a single 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 templates designed to ease constraining common algorithm operations.

Defined in header <iterator>
Defined in namespace std
Indirect callable concepts
IndirectUnaryInvocableIndirectRegularUnaryInvocable	specifies that a callable type can be invoked with the result of dereferencing a Readable type (concept)
IndirectUnaryPredicate	specifies that a callable type, when invoked with the result of dereferencing a Readable type, satisfies Predicate (concept)
IndirectRelation	specifies that a callable type, when invoked with the result of dereferencing two Readable types, satisfies Predicate (concept)
IndirectStrictWeakOrder	specifies that a callable type, when invoked with the result of dereferencing two Readable types, satisfies StrictWeakOrder (concept)
Common algorithm requirements
IndirectlyMovable	specifies that values may be moved from a Readable type to a Writable type (concept)
IndirectlyMovableStorable	specifies that values may be moved from a Readable type to a Writable type and that the move may be performed via an intermediate object (concept)
IndirectlyCopyable	specifies that values may be copied from a Readable type to a Writable type (concept)
IndirectlyCopyableStorable	specifies that values may be copied from a Readable type to a Writable type and that the copy may be performed via an intermediate object (concept)
IndirectlySwappable	specifies that the values referenced by two Readable types can be swapped (concept)
IndirectlyComparable	specifies that the values referenced by two Readable types can be compared (concept)
Permutable	specifies the common requirements of algorithms that reorder elements in place (concept)
Mergeable	specifies the requirements of algorithms that merge sorted sequences into an output sequence by copying elements (concept)
Sortable	specifies the common requirements of algorithms that permute sequences into ordered sequences (concept)
Utilities
indirect_result_t	computes the result of invoking a callable object on the result of dereferencing some set of Readable types (alias template)
projected	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
all_ofany_ofnone_of	checks if a predicate is true for all, any or none of the elements in a range (niebloid)
for_each	applies a function to a range of elements (niebloid)
countcount_if	returns the number of elements satisfying specific criteria (niebloid)
mismatch	finds the first position where two ranges differ (niebloid)
equal	determines if two sets of elements are the same (niebloid)
lexicographical_compare	returns true if one range is lexicographically less than another (niebloid)
findfind_iffind_if_not	finds the first element satisfying specific criteria (niebloid)
find_end	finds the last sequence of elements in a certain range (niebloid)
find_first_of	searches for any one of a set of elements (niebloid)
adjacent_find	finds the first two adjacent items that are equal (or satisfy a given predicate) (niebloid)
search	searches for a range of elements (niebloid)
search_n	searches for a number consecutive copies of an element in a range (niebloid)
Modifying sequence operations
copycopy_if	copies a range of elements to a new location (niebloid)
copy_n	copies a number of elements to a new location (niebloid)
copy_backward	copies a range of elements in backwards order (niebloid)
move	moves a range of elements to a new location (niebloid)
move_backward	moves a range of elements to a new location in backwards order (niebloid)
fill	assigns a range of elements a certain value (niebloid)
fill_n	assigns a value to a number of elements (niebloid)
transform	applies a function to a range of elements (niebloid)
generate	saves the result of a function in a range (niebloid)
generate_n	saves the result of N applications of a function (niebloid)
removeremove_if	removes elements satisfying specific criteria (niebloid)
remove_copyremove_copy_if	copies a range of elements omitting those that satisfy specific criteria (niebloid)
replacereplace_if	replaces all values satisfying specific criteria with another value (niebloid)
replace_copyreplace_copy_if	copies a range, replacing elements satisfying specific criteria with another value (niebloid)
swap_ranges	swaps two ranges of elements (niebloid)
reverse	reverses the order of elements in a range (niebloid)
reverse_copy	creates a copy of a range that is reversed (niebloid)
rotate	rotates the order of elements in a range (niebloid)
rotate_copy	copies and rotate a range of elements (niebloid)
shuffle	randomly re-orders elements in a range (niebloid)
unique	removes consecutive duplicate elements in a range (niebloid)
unique_copy	creates a copy of some range of elements that contains no consecutive duplicates (niebloid)
Partitioning operations
is_partitioned	determines if the range is partitioned by the given predicate (niebloid)
partition	divides a range of elements into two groups (niebloid)
partition_copy	copies a range dividing the elements into two groups (niebloid)
stable_partition	divides elements into two groups while preserving their relative order (niebloid)
partition_point	locates the partition point of a partitioned range (niebloid)
Sorting operations
is_sorted	checks whether a range is sorted into ascending order (niebloid)
is_sorted_until	finds the largest sorted subrange (niebloid)
sort	sorts a range into ascending order (niebloid)
partial_sort	sorts the first N elements of a range (niebloid)
partial_sort_copy	copies and partially sorts a range of elements (niebloid)
stable_sort	sorts a range of elements while preserving order between equal elements (niebloid)
nth_element	partially sorts the given range making sure that it is partitioned by the given element (niebloid)
Binary search operations (on sorted ranges)
lower_bound	returns an iterator to the first element not less than the given value (niebloid)
upper_bound	returns an iterator to the first element greater than a certain value (niebloid)
binary_search	determines if an element exists in a certain range (niebloid)
equal_range	returns range of elements matching a specific key (niebloid)
Set operations (on sorted ranges)
merge	merges two sorted ranges (niebloid)
inplace_merge	merges two ordered ranges in-place (niebloid)
includes	returns true if one set is a subset of another (niebloid)
set_difference	computes the difference between two sets (niebloid)
set_intersection	computes the intersection of two sets (niebloid)
set_symmetric_difference	computes the symmetric difference between two sets (niebloid)
set_union	computes the union of two sets (niebloid)
Heap operations
is_heap	checks if the given range is a max heap (niebloid)
is_heap_until	finds the largest subrange that is a max heap (niebloid)
make_heap	creates a max heap out of a range of elements (niebloid)
push_heap	adds an element to a max heap (niebloid)
pop_heap	removes the largest element from a max heap (niebloid)
sort_heap	turns a max heap into a range of elements sorted in ascending order (niebloid)
Minimum/maximum operations
max	returns the greater of the given values (niebloid)
max_element	returns the largest element in a range (niebloid)
min	returns the smaller of the given values (niebloid)
min_element	returns the smallest element in a range (niebloid)
minmax	returns the smaller and larger of two elements (niebloid)
minmax_element	returns the smallest and the largest elements in a range (niebloid)
Permutation operations
is_permutation	determines if a sequence is a permutation of another sequence (niebloid)
next_permutation	generates the next greater lexicographic permutation of a range of elements (niebloid)
prev_permutation	generates the next smaller lexicographic permutation of a range of elements (niebloid)

Constrained uninitialized memory algorithms

Defined in header <memory>
Defined in namespace std::ranges
uninitialized_copy (C++20)	copies a range of objects to an uninitialized area of memory (niebloid)
uninitialized_copy_n (C++20)	copies a number of objects to an uninitialized area of memory (niebloid)
uninitialized_fill (C++20)	copies an object to an uninitialized area of memory, defined by a range (niebloid)
uninitialized_fill_n (C++20)	copies an object to an uninitialized area of memory, defined by a start and a count (niebloid)
uninitialized_move (C++20)	moves a range of objects to an uninitialized area of memory (niebloid)
uninitialized_move_n (C++20)	moves a number of objects to an uninitialized area of memory (niebloid)
uninitialized_default_construct (C++20)	constructs objects by default-initialization in an uninitialized area of memory, defined by a range (niebloid)
uninitialized_default_construct_n (C++20)	constructs objects by default-initialization in an uninitialized area of memory, defined by a start and count (niebloid)
uninitialized_value_construct (C++20)	constructs objects by value-initialization in an uninitialized area of memory, defined by a range (niebloid)
uninitialized_value_construct_n (C++20)	constructs objects by value-initialization in an uninitialized area of memory, defined by a start and a count (niebloid)
destroy_at (C++20)	destroys an object at a given address (niebloid)
destroy (C++20)	destroys a range of objects (niebloid)
destroy_n (C++20)	destroys a number of objects in a range (niebloid)