From 0fd4bf37f9b88a1e07f8fc83503306a34135ab9d Mon Sep 17 00:00:00 2001
From: Alissa Rao <lymia@lymiahugs.com>
Date: Tue, 5 Apr 2022 00:50:15 -0700
Subject: [PATCH] Add a new std feature for enumset. Fixes #34

---
 .travis.yml               |  5 +++--
 enumset/Cargo.toml        |  2 ++
 enumset_derive/Cargo.toml |  2 +-
 enumset_derive/src/lib.rs | 24 +++++++++++++++++-------
 4 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 5d75b66..8a378b4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,5 +11,6 @@ script:
   - cd "${TRAVIS_BUILD_DIR}/enumset"
   - cargo test
   - cargo test --features serde
-  - cargo test --release
-  - cargo test --features serde --release
+  - cargo test --features alloc
+  - cargo test --features std
+  - cargo test --release --all-features
diff --git a/enumset/Cargo.toml b/enumset/Cargo.toml
index 3cf07d1..4c51da1 100644
--- a/enumset/Cargo.toml
+++ b/enumset/Cargo.toml
@@ -20,6 +20,8 @@ maintenance = { status = "actively-developed" }
 
 [features]
 serde = ["serde2", "enumset_derive/serde"]
+alloc = []
+std = ["alloc", "enumset_derive/proc-macro-crate"]
 
 [dependencies]
 enumset_derive = { version = "0.5.6", path = "../enumset_derive" }
diff --git a/enumset_derive/Cargo.toml b/enumset_derive/Cargo.toml
index 882b742..def3be1 100644
--- a/enumset_derive/Cargo.toml
+++ b/enumset_derive/Cargo.toml
@@ -22,4 +22,4 @@ darling = { version = "0.13.0", default-features = false }
 syn = "1"
 quote = "1"
 proc-macro2 = "1"
-proc-macro-crate = "1.1.3"
+proc-macro-crate = { version = "1.1.3", optional = true }
diff --git a/enumset_derive/src/lib.rs b/enumset_derive/src/lib.rs
index b779b8e..76e98f7 100644
--- a/enumset_derive/src/lib.rs
+++ b/enumset_derive/src/lib.rs
@@ -6,7 +6,6 @@ use darling::*;
 use proc_macro::TokenStream;
 use proc_macro2::{TokenStream as SynTokenStream, Literal, Span};
 use std::collections::HashSet;
-use proc_macro_crate::FoundCrate;
 use syn::{*, Result, Error};
 use syn::spanned::Spanned;
 use quote::*;
@@ -241,16 +240,27 @@ impl EnumSetInfo {
 /// Generates the actual `EnumSetType` impl.
 fn enum_set_type_impl(info: EnumSetInfo) -> SynTokenStream {
     let name = &info.name;
+
     let enumset = match &info.crate_name {
         Some(crate_name) => quote!(::#crate_name),
         None => {
-            let crate_name = proc_macro_crate::crate_name("enumset");
-            match crate_name {
-                Ok(FoundCrate::Name(name)) => {
-                    let ident = Ident::new(&name, Span::call_site());
-                    quote!(::#ident)
+            #[cfg(feature = "proc-macro-crate")]
+            {
+                use proc_macro_crate::FoundCrate;
+
+                let crate_name = proc_macro_crate::crate_name("enumset");
+                match crate_name {
+                    Ok(FoundCrate::Name(name)) => {
+                        let ident = Ident::new(&name, Span::call_site());
+                        quote!(::#ident)
+                    }
+                    _ => quote!(::enumset),
                 }
-                _ => quote!(::enumset),
+            }
+
+            #[cfg(not(feature = "proc-macro-crate"))]
+            {
+                quote!(::enumset)
             }
         },
     };
-- 
2.44.0