From 25072c5792b2a2f5551414c922a276ee193d8a99 Mon Sep 17 00:00:00 2001
From: anttib-5 <anttib-5@student.ltu.se>
Date: Fri, 8 Mar 2019 14:00:11 +0100
Subject: [PATCH] bare4_2
---
examples/bare4.rs | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/examples/bare4.rs b/examples/bare4.rs
index 37dd6fc..eee44e0 100644
--- a/examples/bare4.rs
+++ b/examples/bare4.rs
@@ -36,8 +36,8 @@ use address::*;
#[inline(always)]
fn read_u32(addr: u32) -> u32 {
- unsafe { core::ptr::read_volatile(addr as *const _) }
- //core::ptr::read_volatile(addr as *const _)
+ //unsafe { core::ptr::read_volatile(addr as *const _) }
+ core::ptr::read_volatile(addr as *const _)
}
#[inline(always)]
@@ -107,12 +107,14 @@ fn main() -> ! {
//
// What was the error message and explain why.
//
-// ** your answer here **
+// call to unsafe function is unsafe and requires unsafe function or block.
+// This happens because the variable is volatile.
//
// Digging a bit deeper, why do you think `read_volatile` is declared `unsafe`.
// (https://doc.rust-lang.org/core/ptr/fn.read_volatile.html, for some food for thought )
//
-// ** your answer here **
+// The volatile value might not be guaranteed to be the same between reads. So it is declared unsafe since it might not
+// be the same as intended.
//
// Commit your answers (bare4_2)
//
--
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