std::rotl

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros(C++20) Program utilities Variadic functions initializer_list (C++11) is_constant_evaluated (C++20) is_within_lifetime (C++26) source_location (C++20) Coroutine support(C++20) Contract support(C++26) Three-way comparison three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)   is_eqis_ltis_lteq (C++20)(C++20)(C++20)   is_neqis_gtis_gteq (C++20)(C++20)(C++20)

General utilities Function objects Bit manipulation(C++20) bitset hash (C++11) Relational operators(deprecated in C++20) rel_ops::operator!=rel_ops::operator>    rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)   cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) Common vocabulary types pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23)

 

Bit manipulation

bit_cast (C++20)

byteswap (C++23)

Integral powers of 2

has_single_bit (C++20)

bit_ceil (C++20)

bit_floor (C++20)

bit_width (C++20)

Rotating

rotl (C++20)

rotr (C++20)

Counting

countl_zero (C++20)

countl_one (C++20)

countr_zero (C++20)

countr_one (C++20)

popcount (C++20)

Endian

endian (C++20)

 

Defined in header <bit>
template<class T > constexpr T rotl( T x, int s )noexcept;		(since C++20)

Computes the result of bitwise left-rotating the value of x by s positions. This operation is also known as a left circular shift.

Formally, let N be std::numeric_limits<T>::digits and r be s % N.

• If r is ​0​, returns x;
• if r is positive, returns (x << r)|(x >>(N - r));
• if r is negative, returns std::rotr(x, -r).

This overload participates in overload resolution only if T is an unsigned integer type (that is, unsignedchar, unsignedshort, unsignedint, unsignedlong, unsignedlonglong, or an extended unsigned integer type).

Parameters

x	-	value of unsigned integer type
s	-	number of positions to shift

Return value

The result of bitwise left-rotating x by s positions.

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_bitops	201907L	(C++20)	Bit operations

Example

Run this code

#include <bit>#include <bitset>#include <cstdint>#include <iostream>   int main(){using bin =std::bitset<8>;conststd::uint8_t x{0b00011101};std::cout<< bin(x)<<" <- x\n";for(constint s :{0, 1, 4, 9, -1})std::cout<< bin(std::rotl(x, s))<<" <- rotl(x, "<< s <<")\n";}

Output:

00011101 <- x 00011101 <- rotl(x, 0) 00111010 <- rotl(x, 1) 11010001 <- rotl(x, 4) 00111010 <- rotl(x, 9) 10001110 <- rotl(x, -1)

See also

rotr (C++20)	computes the result of bitwise right-rotation (function template)
operator<<=operator>>=operator<<operator>>	performs binary shift left and shift right (public member function of std::bitset<N>)