Const-trig

This crate exists to provide const versions of functions, such as cos, sin, etc.

Note that this crate requires nightly Rust to unify behaviour of functions.

Crate is no longer needed when all this function will be const in std.

Any function, such as cos, sin from std can be accessed as const_trig::cos.

There aren't all trig functions, but if you want to add them, you can open a GitHub issue (someday I will read it) :) Usage:

use const_trig::{ToDegrees, ToRadians};

macro_rules! cmp {
   ($fn:ident, $e:expr) => {
       println!(concat!("const_trig::", stringify!($fn), " = {}"), const_trig::$fn($e, None));
       println!(concat!("std ", stringify!($fn), " = {}\n"), $e.$fn());
   };

   ($fn:ident, $lib:expr, $std:expr) => {
       println!(concat!("const_trig::", stringify!($fn), " = {}"), const_trig::$fn($lib, None));
       println!(concat!("std ", stringify!($fn), " = {}\n"), $std.$fn());
   };

   (! $fn:ident, $e:expr, $fnstd:ident) => {
       println!(concat!("const_trig::", stringify!($fn), " = {}"), const_trig::$fn($e, None));
       println!(concat!("std ", stringify!($fnstd), " = {}\n"), $e.$fnstd());
   };
}

fn main() {
   let sixty_degrees = 60.0f32.degrees().radians().get();
   cmp!(sin, sixty_degrees.radians(), sixty_degrees);
   cmp!(cos, sixty_degrees.radians(), sixty_degrees);

   cmp!(sqrt, 4.0f64);
   cmp!(sqrt, 2.0f64);

   cmp!(ln, 10.0f64);
   cmp!(ln, core::f64::consts::E);

   cmp!(! lg, core::f64::consts::E, log10);

   cmp!(! lb, 10.0f64, log2);

   println!("const_trig::log = {}", const_trig::log(3.5, 10.0f64, None));
   println!("std log = {}", 3.5f64.log(10.0));

   println!("{}", const_trig::root(34.0, 5, None))
}