std::log2

 

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HUGE_VALFHUGE_VALHUGE_VALL (C++11)(C++11) INFINITY (C++11) NAN (C++11) math_errhandlingMATH_ERRNOMATH_ERREXCEPT (C++11)	FP_NORMALFP_SUBNORMALFP_ZEROFP_INFINITEFP_NAN (C++11)(C++11)(C++11)(C++11)(C++11)

 

Defined in header <cmath>
float       log2( float arg );		(since C++11)
double      log2( double arg );		(since C++11)
long double log2( long double arg );		(since C++11)
double      log2( Integral arg );		(since C++11)

Computes the base 2 logarithm of arg.

Parameters

arg

-

value of floating-point or Integral type

Return value

log
2(arg)

Domain error occurs if arg is negative. NAN is returned in that case.

Range error occurs if arg is ​0​. -HUGE_VAL is returned in that case.

See also

log	computes natural (base e) logarithm (to base e) (ln(x)) (function)
exp2 (C++11)	returns 2 raised to the given power (2x) (function)
log10	computes common (base 10) logarithm (log10(x)) (function)
C documentation for log2