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std::log2

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< cpp‎ | numeric‎ | math
 
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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.

[edit] Parameters

arg - value of floating-point or Integral type

[edit] 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.

[edit] See also

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