std::iota

 

C++

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Technical Specifications

 

Algorithm library

Execution policies (C++17)
is_execution_policy	execution::seqexecution::parexecution::par_unseq	execution::sequenced_policyexecution::parallel_policyexecution::parallel_unsequenced_policy
Non-modifying sequence operations
all_ofany_ofnone_of (C++11)(C++11)(C++11) for_each for_each_n (C++17)	countcount_if mismatch equal lexicographical_compare	findfind_iffind_if_not (C++11) find_end find_first_of	adjacent_find search search_n
Modifying sequence operations
copycopy_if (C++11) copy_n (C++11) copy_backward move (C++11) move_backward (C++11) transform	fill fill_n generate generate_n swap iter_swap swap_ranges sample (C++17)	removeremove_if replacereplace_if reverse rotate unique random_shuffle (until C++17)	remove_copyremove_copy_if replace_copyreplace_copy_if reverse_copy rotate_copy unique_copy shuffle (C++11)
Operations on uninitialized storage
uninitialized_copy uninitialized_move (C++17)	uninitialized_copy_n (C++11) uninitialized_move_n (C++17)	uninitialized_fill	uninitialized_fill_n
Partitioning operations
is_partitioned (C++11) partition_point (C++11)	partition partition_copy (C++11)	stable_partition
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is_sorted (C++11) is_sorted_until (C++11)	sort stable_sort	partial_sort partial_sort_copy	nth_element
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lower_bound	upper_bound	binary_search	equal_range
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merge inplace_merge	set_difference set_intersection	set_symmetric_difference set_union	includes
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is_heap (C++11) is_heap_until (C++11)	make_heap sort_heap	push_heap pop_heap
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max max_element	min min_element	minmax (C++11) minmax_element (C++11)	clamp (C++17)
Permutations
is_permutation (C++11)	next_permutation	prev_permutation
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)
C library
qsort	bsearch

 

Defined in header <numeric>
template< class ForwardIterator, class T > void iota( ForwardIterator first, ForwardIterator last, T value );		(since C++11)

Fills the range [first, last) with sequentially increasing values, starting with value and repetitively evaluating ++value.

Equivalent operation:

*(d_first)   = value;
*(d_first+1) = ++value;
*(d_first+2) = ++value;
*(d_first+3) = ++value;
...

Parameters

first, last	-	the range of elements to fill with sequentially increasing values starting with value
value	-	initial value to store, the expression ++value must be well-formed

Return value

(none)

Complexity

Exactly last - first increments and assignments.

Possible implementation

template<class ForwardIterator, class T> void iota(ForwardIterator first, ForwardIterator last, T value) { while(first != last) { *first++ = value; ++value; } }

Notes

The function is named after the integer function ⍳ from the programming language APL. It was one of the STL components that were not included in C++98, but eventually made it into the standard library in C++11.