From 3a61a0b70ce77a67658a007f0ffa00029de249b0 Mon Sep 17 00:00:00 2001
From: Ruben De Smet <ruben.de.smet@rubdos.be>
Date: Thu, 28 May 2020 10:28:28 +0200
Subject: [PATCH] Make Scalar::from_bits a const fn.

const_fn is stable since Rust 1.31
(https://github.com/rust-lang/rust/pull/54835) and enables calling
`Scalar::from_bits(..)` from other const fn contexts, potentially
saving some overhead here and there.

Especially useful in contexts where constants are being built from a bit
pattern.
---
 src/scalar.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/scalar.rs b/src/scalar.rs
index d365d25f1..95493c247 100644
--- a/src/scalar.rs
+++ b/src/scalar.rs
@@ -243,7 +243,7 @@ impl Scalar {
     /// This function is intended for applications like X25519 which
     /// require specific bit-patterns when performing scalar
     /// multiplication.
-    pub fn from_bits(bytes: [u8; 32]) -> Scalar {
+    pub const fn from_bits(bytes: [u8; 32]) -> Scalar {
         let mut s = Scalar{bytes};
         // Ensure that s < 2^255 by masking the high bit
         s.bytes[31] &= 0b0111_1111;