std::countl_one(3)

👑 std::countl_one (3) 👑

manual: C++ Standard Libary 💅

okay bestie, welcome to the C++ Standard Libary page for std::countl_one — yes, the manual name is literally “C++ Standard Libary,” and we are keeping it exactly as-is. This one is all about counting consecutive 1 bits from the left side, and it’s lowkey iconic. 🦋

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✨ NAME ✨

std::countl_one - std::countl_one

✨ Synopsis ✨

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

Returns the number of consecutive 1 ("one") 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, 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 1 bits in the value of x, starting from the most significant bit. No cap, that’s just what it returns. 💖

🧚 Notes 🧚

Feature-test macro vibe check:

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

💖 Example 💖

// Run this code

        #include <bit>
        #include <bitset>
        #include <cstdint>
        #include <iostream>

        int main()
        {
            for (const std::uint8_t i : {0, 0b11111111, 0b01111111,
       0b11100011})
                std::cout << "countl_one( " << std::bitset<8>(i) << " ) = "
                          << std::countl_one(i) << '\n';
        }

🌈 Output 🌈

countl_one( 00000000 ) = 0
countl_one( 11111111 ) = 8
countl_one( 01111111 ) = 0
countl_one( 11100011 ) = 3

👑 See also 👑

• countl_zero — counts the number of consecutive 0 bits, starting from the most significant bit (C++20) (function template)
• countr_zero — counts the number of consecutive 0 bits, starting from the least significant bit (C++20) (function template)
• countr_one — counts the number of consecutive 1 bits, starting from the least significant bit (C++20) (function template)
• popcount — counts the number of 1 bits in an unsigned integer (C++20) (function template)
• has_single_bit — checks if a number is an integral power of 2 (C++20) (function template)
• count — returns the number of bits set to true (public member function of std::bitset<N>)
• all — checks if all, any or none of the bits are set to true (public member function of std::bitset<N>)
• any — checks if all, any or none of the bits are set to true (public member function of std::bitset<N>)
• none — checks if all, any or none of the bits are set to true (public member function of std::bitset<N>)

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okay that’s the whole page bestie! source/version: http://cppreference.com; date: 2024.06.10; page: std::countl_one(3) — mwah 💋✨