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std::countr_zero(3)	       C++ Standard Libary	     std::countr_zero(3)

NAME
     std::countr_zero - std::countr_zero

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

	Returns  the  number  of  consecutive 0 bits in the value of x, starting
     from the least
	significant bit ("right").

	This overload participates in overload resolution only if T  is  an  un-
     signed integer
	type  (that  is,  unsigned  char, unsigned short, unsigned int, unsigned
     long, unsigned
	long long, 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
     least
	significant bit.

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()
      {
	  for (const std::uint8_t i : {0, 0b11111111, 0b00011100, 0b00011101})
	      std::cout << "countr_zero( " << std::bitset<8>(i) << " ) = "
			<< std::countr_zero(i) << '\n';
      }

Output:
      countr_zero( 00000000 ) = 8
      countr_zero( 11111111 ) = 0
      countr_zero( 00011100 ) = 2
      countr_zero( 00011101 ) = 0

See also
	countl_zero  counts  the number of consecutive 0 bits, starting from the
     most
	(C++20)     significant bit
		    (function template)
	countl_one  counts the number of consecutive 1 bits, starting  from  the
     most
	(C++20)     significant bit
		    (function template)
	countr_one   counts  the number of consecutive 1 bits, starting from the
     least
	(C++20)     significant bit
		    (function template)
	popcount    counts the number of 1 bits in an unsigned integer
	(C++20)     (function template)
	all	    checks if all, any or none of the bits are set to true
	any	    (public member function of std::bitset<N>)
	none

http://cppreference.com 	   2024.06.10		     std::countr_zero(3)
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