From 67cdcc2e12118becb823e20a40cc2687f2b8425a Mon Sep 17 00:00:00 2001
From: Adam Carpenter <53hornet@gmail.com>
Date: Wed, 27 Mar 2019 15:32:37 -0400
Subject: Started Rust in Action MEAP.

---
 meap/meap-code/ch6/ch6-memscan-1/Cargo.lock  |  4 ++++
 meap/meap-code/ch6/ch6-memscan-1/Cargo.toml  |  6 ++++++
 meap/meap-code/ch6/ch6-memscan-1/src/main.rs | 14 ++++++++++++++
 3 files changed, 24 insertions(+)
 create mode 100644 meap/meap-code/ch6/ch6-memscan-1/Cargo.lock
 create mode 100644 meap/meap-code/ch6/ch6-memscan-1/Cargo.toml
 create mode 100644 meap/meap-code/ch6/ch6-memscan-1/src/main.rs

(limited to 'meap/meap-code/ch6/ch6-memscan-1')

diff --git a/meap/meap-code/ch6/ch6-memscan-1/Cargo.lock b/meap/meap-code/ch6/ch6-memscan-1/Cargo.lock
new file mode 100644
index 0000000..622c46c
--- /dev/null
+++ b/meap/meap-code/ch6/ch6-memscan-1/Cargo.lock
@@ -0,0 +1,4 @@
+[[package]]
+name = "ch6-memscan-1"
+version = "0.1.0"
+
diff --git a/meap/meap-code/ch6/ch6-memscan-1/Cargo.toml b/meap/meap-code/ch6/ch6-memscan-1/Cargo.toml
new file mode 100644
index 0000000..9819069
--- /dev/null
+++ b/meap/meap-code/ch6/ch6-memscan-1/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "ch6-memscan-1"
+version = "0.1.0"
+authors = ["Tim McNamara <code@timmcnamara.co.nz>"]
+
+[dependencies]
diff --git a/meap/meap-code/ch6/ch6-memscan-1/src/main.rs b/meap/meap-code/ch6/ch6-memscan-1/src/main.rs
new file mode 100644
index 0000000..b92da20
--- /dev/null
+++ b/meap/meap-code/ch6/ch6-memscan-1/src/main.rs
@@ -0,0 +1,14 @@
+fn main() {
+    let mut n_nonzero = 0;  
+
+    for i in 0..10000 { 
+        let ptr = i as *const u8; // <1> Convert `i` to a `pass:[*const T]`, a "`raw pointer`" of type `u8`. Raw pointers allow programmers to inspect raw memory addresses. We treat every address as a unit, ignoring the fact that most values span multiple bytes.
+        let byte_at_addr = unsafe { *ptr }; // <2> _Dereference_ the pointer. That is, read the value at address `i`. Another way of saying this is read the value being pointed to.
+
+        if byte_at_addr != 0 {
+            n_nonzero += 1;
+        }
+    }
+
+    println!("non-zero bytes in memory: {}", n_nonzero);
+}
\ No newline at end of file
-- 
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