Support no_std

Co-Authored-By: Fredrick Brennan <copypaste@kittens.ph>

Author: roblabla

Cargo.toml

@@ -10,4 +10,5 @@ homepage = "https://github.com/andersk/enum_primitive-rs"
 readme = "README.md"
 
 [dependencies.num-traits]
-version = "^0.1"
+version = "0.2"
+default-features = false

src/lib.rs

@@ -52,10 +52,11 @@
 //! }
 //! ```
 
+#![no_std]
 
 extern crate num_traits;
 
-pub use std::option::Option;
+pub use core::option::Option;
 pub use num_traits::FromPrimitive;
 
 /// Helper macro for internal use by `enum_from_primitive!`.
@@ -75,7 +76,6 @@ macro_rules! enum_from_primitive_impl_ty {
 
 /// Helper macro for internal use by `enum_from_primitive!`.
 #[macro_export]
-#[macro_use(enum_from_primitive_impl_ty)]
 macro_rules! enum_from_primitive_impl {
     ($name:ident, $( $variant:ident )*) => {
         impl $crate::FromPrimitive for $name {
@@ -88,7 +88,6 @@ macro_rules! enum_from_primitive_impl {
 /// Wrap this macro around an `enum` declaration to get an
 /// automatically generated implementation of `num::FromPrimitive`.
 #[macro_export]
-#[macro_use(enum_from_primitive_impl)]
 macro_rules! enum_from_primitive {
     (
         $( #[$enum_attr:meta] )*