From f9644c16f3156025d83d3dc1262ac35d9ae89588 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Fri, 28 Feb 2020 09:21:25 +0100
Subject: [PATCH] add comment to check_data

---
 src/librustc/mir/interpret/value.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/librustc/mir/interpret/value.rs b/src/librustc/mir/interpret/value.rs
index 2c146b5d7b4..0e14089eebc 100644
--- a/src/librustc/mir/interpret/value.rs
+++ b/src/librustc/mir/interpret/value.rs
@@ -170,6 +170,10 @@ impl<Tag> From<Double> for Scalar<Tag> {
 }
 
 impl Scalar<()> {
+    /// Make sure the `data` fits in `size`.
+    /// This is guaranteed by all constructors here, but since the enum variants are public,
+    /// it could still be violated (even though no code outside this file should
+    /// construct `Scalar`s).
     #[inline(always)]
     fn check_data(data: u128, size: u8) {
         debug_assert_eq!(