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std::pow

From cppreference.com
< cpp‎ | numeric‎ | math
 
 
 
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Defined in header <cmath>
float       pow( float base, float exp );
(1)
double      pow( double base, double exp );
(2)
long double pow( long double base, long double exp );
(3)
float       pow( float base, int iexp );
(4) (until C++11)
double      pow( double base, int iexp );
(5) (until C++11)
long double pow( long double base, int iexp );
(6) (until C++11)
Promoted    pow( Arithmetic1 base, Arithmetic2 exp );
(7) (since C++11)

Computes the value of base raised to the power exp or iexp.

7) A set of overloads or a function template for all combinations of arguments of arithmetic type not covered by 1-3). If any argument has integral type, it is cast to double. If any argument is long double, then the return type Promoted is also long double, otherwise the return type is always double.

Contents

[edit] Parameters

base - base as a value of floating-point or integral type
exp - exponent as a value of floating-point or integral type
iexp - exponent as integer value

[edit] Return value

base raised by power (exp or iexp).

If base is finite and negative and exp is finite and non-integer, a domain error occurs and a range error may occur.

If base is zero and exp is zero, a domain error occurs.

If base is zero and exp is negative, a domain error or a pole error may occur.

If domain error occurs and math_errhandling & MATH_ERRNO is nonzero, errno is set to EDOM.

If domain error occurs and math_errhandling & MATH_ERREXCEPT is nonzero, FE_INVALID is raised.

If range error occurs and math_errhandling & MATH_ERRNO is nonzero, errno is set to ERANGE.

If range error occurs and math_errhandling & MATH_ERREXCEPT is nonzero, FE_OVERFLOW is raised.

If the implementation supports IEEE floating-point arithmetic (IEC 60559),

pow(+0, exp), where exp is a negative odd integer, returns +∞ and raises FE_DIVBYZERO
pow(-0, exp), where exp is a negative odd integer, returns -∞ and raises FE_DIVBYZERO
pow(±0, exp), where exp is negative, finite, and is an even integer or a non-integer, returns +∞ and raises FE_DIVBYZERO
pow(±0, -) returns +∞ and may raise FE_DIVBYZERO
pow(+0, exp), where exp is a positive odd integer, returns +0
pow(-0, exp), where exp is a positive odd integer, returns -0
pow(±0, exp), where exp is positive non-integer or a positive even integer, returns +0
pow(-1, ±∞) returns 1
pow(+1, exp) returns 1 for any exp, even when exp is NaN
pow(base, ±0) returns 1 for any base, even when base is NaN
pow(base, exp) returns NaN and raises FE_INVALID if base is finite and negative and exp is finite and non-integer.
pow(base, -) returns +∞ for any |base|<1
pow(base, -) returns +0 for any |base|>1
pow(base, +) returns +0 for any |base|<1
pow(base, +) returns +∞ for any |base|>1
pow(-∞, exp) returns -0 if exp is a negative odd integer
pow(-∞, exp) returns +0 if exp is a negative non-integer or even integer
pow(-∞, exp) returns -∞ if exp is a positive odd integer
pow(-∞, exp) returns +∞ if exp is a positive non-integer or even integer
pow(+∞, exp) returns +0 for any negative exp
pow(+∞, exp) returns +∞ for any positive exp
(since C++11)


[edit] Notes

pow(float, int) returns float until C++11 (per overload 4) but returns double since C++11 (per overload 7)

[edit] See also

returns e raised to the given power (ex)
(function) [edit]
computes natural (base e) logarithm (to base e) (ln(x))
(function) [edit]
computes square root (x)
(function) [edit]
(C++11)
computes cubic root (3x)
(function) [edit]
complex power, one or both arguments may be a complex number
(function template) [edit]
applies the function std::pow to two valarrays or a valarray and a value
(function template) [edit]