Provides the nz macro for constructing a std::num::NonZero* from an integer constant.

The nz macro can infer the argument's type from the inferred NonZero* return type, while some alternative macros always require that the argument's type is specified.

Example

Usage

use notzero::nz;
use std::num::NonZeroU64;

let two = nz!(2u16); // returns a `NonZeroU16`
assert_eq!(two.get(), 2u16);

// infers the argument's type from the returned `NonZero`
const THREE: NonZeroU64 = nz!(3); 
assert_eq!(THREE.get(), 3u64);

const FOUR: i8 = -4;
let fourz = nz!(FOUR); // returns a `NonZeroI8`
assert_eq!(fourz.get(), -4i8);

Zero argument

const ZERO: u8 = 0;
let _ = notzero::nz!(ZERO);

the above code produces this compile-time error:

error[E0080]: evaluation of `main::_doctest_main_src_lib_rs_27_0::{constant#0}` failed
 --> src/lib.rs:32:9
  |
8 | let _ = notzero::nz!(ZERO);
  |         ^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'passed in a `0` argument', src/lib.rs:8:9
  |
  = note: this error originates in the macro `notzero::nz` (in Nightly builds, run with -Z macro-backtrace more info)

No-std support

notzero is #![no_std], it can be used anywhere Rust can be used.

Minimum Supported Rust Version

This crate requires Rust 1.79.0 because it uses const { ... } expressions (also known as "inline const").