# pow function

num pow (num x, num exponent)

Returns `x` to the power of `exponent`.

If `x` is an int and `exponent` is a non-negative int, the result is an int, otherwise both arguments are converted to doubles first, and the result is a double.

For integers, the power is always equal to the mathematical result of `x` to the power `exponent`, only limited by the available memory.

For doubles, `pow(x, y)` handles edge cases as follows:

- if `y` is zero (0.0 or -0.0), the result is always 1.0.
- if `x` is 1.0, the result is always 1.0.
- otherwise, if either `x` or `y` is NaN then the result is NaN.
- if `x` is negative (but not -0.0) and `y` is a finite non-integer, the result is NaN.
- if `x` is Infinity and `y` is negative, the result is 0.0.
- if `x` is Infinity and `y` is positive, the result is Infinity.
- if `x` is 0.0 and `y` is negative, the result is Infinity.
- if `x` is 0.0 and `y` is positive, the result is 0.0.
- if `x` is -Infinity or -0.0 and `y` is an odd integer, then the result is `-pow(-x ,y)`.
- if `x` is -Infinity or -0.0 and `y` is not an odd integer, then the result is the same as `pow(-x , y)`.
- if `y` is Infinity and the absolute value of `x` is less than 1, the result is 0.0.
- if `y` is Infinity and `x` is -1, the result is 1.0.
- if `y` is Infinity and the absolute value of `x` is greater than 1, the result is Infinity.
- if `y` is -Infinity, the result is `1/pow(x, Infinity)`.

This corresponds to the `pow` function defined in the IEEE Standard 754-2008.

Notice that an int result cannot overflow, but a double result might be double.infinity.

## Implementation

    external num pow(num x, num exponent);