std::countl_zero
From cppreference.com
C++
Utilities library
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Bit manipulation
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(C++20)
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countl_zero (C++20) |
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(C++20)
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Defined in header <bit>
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template
<
class T >
constexpr int countl_zero( T x ) noexcept ; |
(since C++20) | |
Returns the number of consecutive 0 bits in the value of x
This overload participates in overload resolution only if T is an unsigned integer type (that is, unsigned char, unsigned short, unsigned int, unsigned long, unsigned long long
Parameters
| x | - | value of unsigned integer type |
Return value
The number of consecutive 0 bits in the value of x
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, 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
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(C++20)
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counts the number of consecutive 1 bits, starting from the most significant bit (function template) |
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(C++20)
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counts the number of consecutive 0 bits, starting from the least significant bit (function template) |
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(C++20)
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counts the number of consecutive 1 bits, starting from the least significant bit (function template) |
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(C++20)
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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>)
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C documentation for stdc_leading_zeros
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