exp2, exp2f, exp2l

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Computes 2 raised to the specified value (ie, 2ˣ ).

Syntax

double exp2(  
   double x  
);  
  
float exp2(  
   float x  
);  // C++ only  
  
long double exp2(  
   long double x  
); // C++ only  
  
float exp2f(  
   float x  
);  
  
long double exp2l(  
   long double x  
);

Parameters

[in] x
The value of the exponent.

Return Value

If successful, returns the base-2 exponent of x (2ˣ) . Otherwise, may return one of the following values:

Issue	Return
`x` = ±0	1
`x` = -INFINITY	+0
`x` = +INFINITY	+INFINITY
`x` = NaN	NaN
Overflow range error	+HUGE_VAL, +HUGE_VALF, or +HUGE_VALL
Underflow range error	correct result, after rounding

Errors are reported as specified in _matherr.

Remarks

Because C++ allows overloading, you can call overloads of exp2 that take and return float and long double types. In a C program, exp2 always takes and returns a double.

Requirements

Routine	C header	C++ header
`exp`, `expf`, `expl`	<math.h>	<cmath>

For additional compatibility information, see Compatibility.

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