Remove the std feature.

Cargo.toml

@@ -30,5 +30,4 @@ version = "0.2"
 default-features = false
 
 [features]
-default = ["std"]
-std = []
+default = []

README.md

@@ -10,10 +10,7 @@ This is a pure Rust implementation of the Jubjub elliptic curve group and its as
 * **This implementation has not been reviewed or audited. Use at your own risk.**
 * This implementation targets Rust `1.36` or later.
 * All operations are constant time unless explicitly noted.
-
-## Features
-
-* `std` (on by default): Enables APIs that leverage the Rust standard library.
+* This implementation does not require the Rust standard library.
 
 ## [Documentation](https://docs.rs/jubjub)
 

src/fr.rs

@@ -595,7 +595,6 @@ fn test_inv() {
     assert_eq!(inv, INV);
 }
 
-#[cfg(feature = "std")]
 #[test]
 fn test_debug() {
     assert_eq!(

src/lib.rs

@@ -22,14 +22,13 @@
 #![deny(missing_debug_implementations)]
 #![deny(missing_docs)]
 #![deny(unsafe_code)]
-
 // This lint is described at
 // https://rust-lang.github.io/rust-clippy/master/index.html#suspicious_arithmetic_impl
 // In our library, some of the arithmetic will necessarily involve various binary
 // operators, and so this lint is triggered unnecessarily.
 #![allow(clippy::suspicious_arithmetic_impl)]
 
-#[cfg(feature = "std")]
+#[cfg(test)]
 #[macro_use]
 extern crate std;
 
@@ -974,7 +973,6 @@ fn test_assoc() {
     );
 }
 
-#[cfg(feature = "std")]
 #[test]
 fn test_batch_normalize() {
     let mut p = ExtendedPoint::from(AffinePoint {