From cppreference.com
Defined in header
template<classT>constexprintcountl_zero(Tx)noexcept;(since C++20)Returns the number of consecutive 0 bits in the value of x, starting from the most significant bit (“left”).
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 Return value
The number of consecutive 0 bits in the value of x, starting from the most significant bit.
Notes
macroValueStdFeature
(C++20)
Example
Run this code
#include<bit>#include<bitset>#include<cstdint>#include<iostream>intmain(){for(conststd::uint8_ti:{0,0b11111111,0b11110000,0b00011110})std::cout<<"countl_zero( "<<std::bitset<8>(i)<<" ) = "<<std::countl_zero(i)<<'\n';}Output:
countl_zero( 00000000 ) = 8 countl_zero( 11111111 ) = 0 countl_zero( 11110000 ) = 0 countl_zero( 00011110 ) = 3 See also
(C++20)
counts the number of consecutive 1 bits, starting from the most significant bit
(function template)
(C++20)
counts the number of consecutive 0 bits, starting from the least significant bit
(function template)
(C++20)
counts the number of consecutive 1 bits, starting from the least significant bit
(function template)
(C++20)
counts the number of 1 bits in an unsigned integer
(function template)
checks if all, any or none of the bits are set to true
(public member function of std::bitset<N>)
for stdc_leading_zeros