bare4_2

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)]
@@ -104,12 +104,18 @@ fn main() -> ! {
 //    What was the error message and explain why.
 //
 //    ** your answer here **
+//      error[E0133]: call to unsafe function is unsafe and requires unsafe function or block
+//      read_volatile is an unsafe function, which requires it to be called under a unsafe block.
 //
 //    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 **
 //
+//      read_volatile is inherently unsafe because reading a volatile variable is, indeed volatile
+//      A volatile variable is volatile because it moves the value out of the address without
+//      preventing further usage of that specific address.
+//
 //    Commit your answers (bare4_2)
 //
 // 3. Volatile read/writes are explicit *volatile operations* in Rust, while in C they