I'm a little confused on why pow behaves so differently when switching from an int to a uint for the exponent.

import std.math : pow;
import std.stdio : writeln;

void main()
{

	float x = 2;
	int y1 = 1;
	uint y2 = 1;

	writeln(pow(x, -y1));  //prints 0.5
	writeln(pow(x, -y2));  //prints inf

}

On Wednesday, 24 August 2016 at 19:16:56 UTC, jmh530 wrote:
> I'm a little confused on why pow behaves so differently when switching from an int to a uint for the exponent.
>
> import std.math : pow;
> import std.stdio : writeln;
>
> void main()
> {
>
> 	float x = 2;
> 	int y1 = 1;
> 	uint y2 = 1;
>
> 	writeln(pow(x, -y1));  //prints 0.5
> 	writeln(pow(x, -y2));  //prints inf
>
> }

-y1 is -1. But -y2 is uint.max, i.e. a pretty large positive number.

The 'u' in "uint" stands for "unsigned". That is, it doesn't know negative numbers. Dont' use uint when you need negative numbers.

On Wednesday, 24 August 2016 at 19:41:35 UTC, ag0aep6g wrote:
>
> -y1 is -1. But -y2 is uint.max, i.e. a pretty large positive number.
>
> The 'u' in "uint" stands for "unsigned". That is, it doesn't know negative numbers. Dont' use uint when you need negative numbers.

Ahh, doh.