exp2, exp2f, exp2l
Visual Studio 2015
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at exp2, exp2f, exp2l.
Computes 2 raised to the specified value (ie, 2ˣ ).
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.
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.
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.
| Routine | C header | C++ header |
|---|---|---|
exp, expf, expl | <math.h> | <cmath> |
For additional compatibility information, see Compatibility.
Show: