Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Supports enum_primitive! with ToPrimitive support. #3

Merged
merged 1 commit into from
Nov 14, 2021
Merged

Supports enum_primitive! with ToPrimitive support. #3

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
143 changes: 142 additions & 1 deletion src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,7 +57,7 @@
extern crate num_traits;

pub use core::option::Option;
pub use num_traits::FromPrimitive;
pub use num_traits::{FromPrimitive, ToPrimitive};

/// Helper macro for internal use by `enum_from_primitive!`.
#[macro_export]
Expand All @@ -74,6 +74,29 @@ macro_rules! enum_from_primitive_impl_ty {
};
}

/// Helper macro for internal use by `enum_to_primitive!`.
#[macro_export]
macro_rules! enum_to_primitive_impl_ty {
($meth:ident, $ty:ty, $name:ident) => {
#[allow(non_upper_case_globals, unused)]
fn $meth(&self) -> $crate::Option<$ty> {
let copy: $name = unsafe { ::std::mem::transmute_copy(self) };
Some(copy as $ty)
}
};
}

/// Helper macro for internal use by `enum_to_primitive!`.
#[macro_export]
macro_rules! enum_to_primitive_impl {
($name:ident) => {
impl $crate::ToPrimitive for $name {
enum_to_primitive_impl_ty! { to_i64, i64, $name }
enum_to_primitive_impl_ty! { to_u64, u64, $name }
}
};
}

/// Helper macro for internal use by `enum_from_primitive!`.
#[macro_export]
macro_rules! enum_from_primitive_impl {
Expand Down Expand Up @@ -193,3 +216,121 @@ macro_rules! enum_from_primitive {
enum_from_primitive_impl! { $name, $( $( $variant )+ )+ }
};
}


/// Wrap this macro around an `enum` declaration to get an
/// automatically generated implementation of `num::FromPrimitive`.
#[macro_export]
macro_rules! enum_primitive {
(
$( #[$enum_attr:meta] )*
enum $name:ident {
$( $( #[$variant_attr:meta] )* $variant:ident ),+ $( = $discriminator:expr, $( $( #[$variant_two_attr:meta] )* $variant_two:ident ),+ )*
}
) => {
$( #[$enum_attr] )*
enum $name {
$( $( #[$variant_attr] )* $variant ),+ $( = $discriminator, $( $( #[$variant_two_attr] )* $variant_two ),+ )*
}
enum_from_primitive_impl! { $name, $( $variant )+ $( $( $variant_two )+ )* }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
enum $name:ident {
$( $( $( #[$variant_attr:meta] )* $variant:ident ),+ = $discriminator:expr ),*
}
) => {
$( #[$enum_attr] )*
enum $name {
$( $( $( #[$variant_attr] )* $variant ),+ = $discriminator ),*
}
enum_from_primitive_impl! { $name, $( $( $variant )+ )* }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
enum $name:ident {
$( $( #[$variant_attr:meta] )* $variant:ident ),+ $( = $discriminator:expr, $( $( #[$variant_two_attr:meta] )* $variant_two:ident ),+ )*,
}
) => {
$( #[$enum_attr] )*
enum $name {
$( $( #[$variant_attr] )* $variant ),+ $( = $discriminator, $( $( #[$variant_two_attr] )* $variant_two ),+ )*,
}
enum_from_primitive_impl! { $name, $( $variant )+ $( $( $variant_two )+ )* }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
enum $name:ident {
$( $( $( #[$variant_attr:meta] )* $variant:ident ),+ = $discriminator:expr ),+,
}
) => {
$( #[$enum_attr] )*
enum $name {
$( $( $( #[$variant_attr] )* $variant ),+ = $discriminator ),+,
}
enum_from_primitive_impl! { $name, $( $( $variant )+ )+ }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
pub enum $name:ident {
$( $( #[$variant_attr:meta] )* $variant:ident ),+ $( = $discriminator:expr, $( $( #[$variant_two_attr:meta] )* $variant_two:ident ),+ )*
}
) => {
$( #[$enum_attr] )*
pub enum $name {
$( $( #[$variant_attr] )* $variant ),+ $( = $discriminator, $( $( #[$variant_two_attr] )* $variant_two ),+ )*
}
enum_from_primitive_impl! { $name, $( $variant )+ $( $( $variant_two )+ )* }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
pub enum $name:ident {
$( $( $( #[$variant_attr:meta] )* $variant:ident ),+ = $discriminator:expr ),*
}
) => {
$( #[$enum_attr] )*
pub enum $name {
$( $( $( #[$variant_attr] )* $variant ),+ = $discriminator ),*
}
enum_from_primitive_impl! { $name, $( $( $variant )+ )* }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
pub enum $name:ident {
$( $( #[$variant_attr:meta] )* $variant:ident ),+ $( = $discriminator:expr, $( $( #[$variant_two_attr:meta] )* $variant_two:ident ),+ )*,
}
) => {
$( #[$enum_attr] )*
pub enum $name {
$( $( #[$variant_attr] )* $variant ),+ $( = $discriminator, $( $( #[$variant_two_attr] )* $variant_two ),+ )*,
}
enum_from_primitive_impl! { $name, $( $variant )+ $( $( $variant_two )+ )* }
enum_to_primitive_impl! { $name }
};

(
$( #[$enum_attr:meta] )*
pub enum $name:ident {
$( $( $( #[$variant_attr:meta] )* $variant:ident ),+ = $discriminator:expr ),+,
}
) => {
$( #[$enum_attr] )*
pub enum $name {
$( $( $( #[$variant_attr] )* $variant ),+ = $discriminator ),+,
}
enum_from_primitive_impl! { $name, $( $( $variant )+ )+ }
enum_to_primitive_impl! { $name }
};
}
50 changes: 50 additions & 0 deletions tests/tests.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -233,3 +233,53 @@ fn documented() {
assert_eq!(Documented::from_i32(17), Some(Documented::A));
assert_eq!(Documented::from_i32(91), None);
}

#[test]
fn to_primitive() {
use ep::ToPrimitive;

mod top {
enum_primitive! {
#[derive(Debug, PartialEq)]
#[repr(u64)]
pub enum EnumU64 {
A = 0xdeadbeefdeadbeef,
B = 0x0,
}
}

enum_primitive! {
#[derive(Debug, PartialEq)]
#[repr(u32)]
pub enum EnumU32 {
A = 0xdeadbeef,
B = 0x0,
}
}

enum_primitive! {
#[derive(Debug, PartialEq)]
#[repr(u16)]
pub enum EnumU16 {
A = 0xdead,
B = 0x0,
}
}

enum_primitive! {
#[derive(Debug, PartialEq)]
#[repr(u8)]
pub enum EnumU8 {
A = 0xde,
B = 0x0,
}
}
}

println!("what {:?}", top::EnumU8::A.to_u8());

assert_eq!(0xdeadbeefdeadbeef, top::EnumU64::A.to_u64().unwrap());
assert_eq!(0xdeadbeef, top::EnumU32::A.to_u32().unwrap());
assert_eq!(0xdead, top::EnumU16::A.to_u16().unwrap());
assert_eq!(0xde, top::EnumU8::A.to_u8().unwrap());
}