Get things to compile after refactor

Cargo.toml

@@ -25,6 +25,7 @@ ark-bls12-377 = "0.4"
 ark-ed-on-bls12-377 = { version = "0.4", features = ["r1cs"] }
 ark-groth16 = { version = "0.4", default-features=false, optional=true }
 ark-snark = { version = "0.4", optional=true }
+cfg-if = "1.0"
 zeroize = {version ="1.7", default-features=false}
 hashbrown = "0.14.3"
 

proptest-regressions/fields/fp/arkworks.txt

@@ -0,0 +1,7 @@
+# Seeds for failure cases proptest has generated in the past. It is
+# automatically read and these particular cases re-run before any
+# novel cases are generated.
+#
+# It is recommended to check this file in to source control so that
+# everyone who runs the test benefits from these saved cases.
+cc cdd619576f50197f2531266a43db3be354532b33cd74b87be7ca92df4a5c0715 # shrinks to a = Fp(0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000)

src/fields/fp.rs

@@ -1,6 +1,31 @@
 // Fiat-crypto generates some unused type aliases, but we don't want to edit the generated code at all.
 #![allow(dead_code)]
 
+use cfg_if::cfg_if;
+
+pub mod arkworks;
 pub mod u32;
 pub mod u64;
-pub mod arkworks;
+
+#[cfg(all(not(feature = "u32"), not(feature = "u64")))]
+// compile_error!("No backend selected. Please select either: 'u32_backend' or 'u64_backend'.");
+#[cfg(all(feature = "u32", feature = "u64"))]
+compile_error!(
+    "Multiple backends selected. Please select only one: 'u32_backend' or 'u64_backend'."
+);
+
+cfg_if! {
+    if #[cfg(feature = "u32")] {
+        pub type Fp = u32::Fp;
+
+        pub mod arkworks_constants {
+            pub use super::u32::arkworks_constants::*;
+        }
+    } else {
+        pub type Fp = u64::Fp;
+
+        pub mod arkworks_constants {
+            pub use super::u64::arkworks_constants::*;
+        }
+    }
+}