From f7e0b277ce610fd91649b34628e148d641d4b183 Mon Sep 17 00:00:00 2001
From: "Christoph J. Scherr" <Christ.Scherr@newtec.de>
Date: Wed, 20 Sep 2023 11:30:50 +0200
Subject: [PATCH] dumping with macro

---
 members/what-is/src/main.rs | 45 ++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/members/what-is/src/main.rs b/members/what-is/src/main.rs
index ea707c9..dcafa2b 100644
--- a/members/what-is/src/main.rs
+++ b/members/what-is/src/main.rs
@@ -1,6 +1,4 @@
 use std::any::{TypeId, type_name};
-use std::mem::*;
-use std::fmt::Debug;
 //* # See what's behind the primitive datatypes of Rust
 //*
 //* This Crate shows off, how primitive Types of rust are stored in memory.
@@ -9,23 +7,34 @@ fn main() {
     let mut items = Vec::new();
     items.push(true);
     items.push(false);
-    dump_type::<bool>(items);
+    investigate!(bool, items);
+
+    let mut items = Vec::new();
+    items.push(String::from("foo"));
+    items.push(String::from("bar"));
+    items.push(String::from("文学"));
+    investigate!(String, items);
 }
 
-fn dump_type<T: Debug + 'static>(items: Vec<T>) {
-    println!("Type:\t{}", type_name::<T>());
-    println!("\tID:\t{:?}", TypeId::of::<T>());
-    println!("\tItems:");
-    unsafe {
-        for (index, item) in items.iter().enumerate() {
-            let pointer = item as *const T;
-            let raw_pointer = pointer as *const u8;
-            println!("\t{index:02x}\titem:\t{item:?}\n\
-                \t\tpointer: {:X?}\n\
-                \t\tmemory: {:X?}",
-                pointer,
-                *raw_pointer,
-            );
+#[macro_export]
+macro_rules! investigate {
+    ($t:ty, $v:tt) => {
+        println!("Type:\t{}", type_name::<$t>());
+        println!("\tID:\t{:?}", TypeId::of::<$t>());
+        println!("\tItems:");
+        unsafe {
+            for (index, item) in $v.iter().enumerate() {
+                let pointer = item as *const $t;
+                let raw_pointer: [u8; std::mem::size_of::<$t>()] = std::mem::transmute(item.clone());
+                println!("\t{index:02x}\titem:\t{item:?}\n\
+                    \t\tpointer: {:X?}\n\
+                    \t\talign: {:#X} B\n\
+                    \t\tmemory: {:X?}\n",
+                    pointer,
+                    std::mem::align_of::<$t>(),
+                    raw_pointer,
+                );
+            }
         }
-    }
+    };
 }