std::log2p1 (3) - Linux Manuals

std::log2p1: std::log2p1


std::log2p1 - std::log2p1


Defined in header <bit>
template< class T > (since C++20)
constexpr T log2p1(T x) noexcept;

If x is not zero, calculates the number of bits needed to store the value x, that is, \(1 + \lfloor log_2(x) \rfloor\)1 + floor(log
2(x)). If x is zero, returns zero.
This overload only participates in overload resolution 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).

Return value

Zero if x is zero; otherwise, one plus the base-2 logarithm of x, with any fractional part discarded.


 This section is incomplete
 Reason: no example