Pow() syntax is inconsistent between floats and ints

[polyfractal]

Brought this up on IRC the other day and was told to make an issue :)

The current syntax for Pow() is confusing/inconsistent for (ignorant) newcomers like myself. For floats, you can do:

let my_float = 5f32;
let pow2 = my_float.pow(2);

But for any of the integers, you need to use the "static" trait function since integers do not implement the Algebraic trait:

let my_int = 5u32;
let pow2 = Int::pow(my_int, 2);

[bluss]

Just a correction, the syntax for the float case has to be one of:

 5.0f.pow(&2.0)
 std::num::pow(5.0, 2.0)

[lilac]

As in the current master branch, there are three pow variants:

std::f32::pow   
std::f64::pow   
std::num::pow

All of them are plain functions, so 5.0f.pow(&2.0) doesn't work now.

Can this issue be closed then?

[huonw]

There's actually more than three version of "power", and 5.0.pow(&2.0) was replaced with .powf.

// trait methods
Real.powf

// freestanding
f32::pow
f64::pow
num::pow // (generic base, integer exponent)
num::powf // (generic Real base & exponent)

In any case, I think the f32 and f64 freestanding pow's should be removed or made private (if possible).

[frewsxcv]

A quick update: a pow() method was added to the Int trait in this pull request, despite it not existing in the numerics reform RFC

[steveklabnik]

This is now all consistent, as far as I can tell. Int has pow, and Float's was changed to powi and powf, but the method syntax works.