From 505e04613f81e5c87a332bbd575c8e15c53535f3 Mon Sep 17 00:00:00 2001
From: Dan Buch <dan@meatballhat.com>
Date: Tue, 26 Sep 2023 06:07:51 -0400
Subject: [PATCH] Up through conversion in RBE

---
 rustbyexample/conversion.d/from_into.rs       | 18 ++++++++++++
 rustbyexample/conversion.d/from_into2.rs      | 19 +++++++++++++
 rustbyexample/conversion.d/string.rs          | 16 +++++++++++
 rustbyexample/conversion.d/string2.rs         |  7 +++++
 .../conversion.d/try_from_try_into.rs         | 28 +++++++++++++++++++
 5 files changed, 88 insertions(+)
 create mode 100644 rustbyexample/conversion.d/from_into.rs
 create mode 100644 rustbyexample/conversion.d/from_into2.rs
 create mode 100644 rustbyexample/conversion.d/string.rs
 create mode 100644 rustbyexample/conversion.d/string2.rs
 create mode 100644 rustbyexample/conversion.d/try_from_try_into.rs

diff --git a/rustbyexample/conversion.d/from_into.rs b/rustbyexample/conversion.d/from_into.rs
new file mode 100644
index 0000000..f81dd91
--- /dev/null
+++ b/rustbyexample/conversion.d/from_into.rs
@@ -0,0 +1,18 @@
+use std::convert::From;
+
+#[allow(dead_code)]
+#[derive(Debug)]
+struct Number {
+    value: i32,
+}
+
+impl From<i32> for Number {
+    fn from(item: i32) -> Self {
+        Number { value: item }
+    }
+}
+
+fn main() {
+    let num = Number::from(30);
+    println!("My number is {:?}", num);
+}
diff --git a/rustbyexample/conversion.d/from_into2.rs b/rustbyexample/conversion.d/from_into2.rs
new file mode 100644
index 0000000..bac7b1a
--- /dev/null
+++ b/rustbyexample/conversion.d/from_into2.rs
@@ -0,0 +1,19 @@
+use std::convert::Into;
+
+#[allow(dead_code)]
+#[derive(Debug)]
+struct Number {
+    value: i32,
+}
+
+impl Into<Number> for i32 {
+    fn into(self) -> Number {
+        Number { value: self }
+    }
+}
+
+fn main() {
+    let int = 5;
+    let num: Number = int.into();
+    println!("My number is {:?}", num);
+}
diff --git a/rustbyexample/conversion.d/string.rs b/rustbyexample/conversion.d/string.rs
new file mode 100644
index 0000000..3fc1c75
--- /dev/null
+++ b/rustbyexample/conversion.d/string.rs
@@ -0,0 +1,16 @@
+use std::fmt;
+
+struct Circle {
+    radius: i32,
+}
+
+impl fmt::Display for Circle {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Circle of radius {}", self.radius)
+    }
+}
+
+fn main() {
+    let circle = Circle { radius: 6 };
+    println!("{}", circle.to_string());
+}
diff --git a/rustbyexample/conversion.d/string2.rs b/rustbyexample/conversion.d/string2.rs
new file mode 100644
index 0000000..e55559c
--- /dev/null
+++ b/rustbyexample/conversion.d/string2.rs
@@ -0,0 +1,7 @@
+fn main() {
+    let parsed: i32 = "5".parse().unwrap();
+    let turbo_parsed = "10".parse::<i32>().unwrap();
+
+    let sum = parsed + turbo_parsed;
+    println!("Sum: {:?}", sum);
+}
diff --git a/rustbyexample/conversion.d/try_from_try_into.rs b/rustbyexample/conversion.d/try_from_try_into.rs
new file mode 100644
index 0000000..8f6c99d
--- /dev/null
+++ b/rustbyexample/conversion.d/try_from_try_into.rs
@@ -0,0 +1,28 @@
+use std::convert::TryFrom;
+use std::convert::TryInto;
+
+#[derive(Debug, PartialEq)]
+struct EvenNumber(i32);
+
+impl TryFrom<i32> for EvenNumber {
+    type Error = ();
+
+    fn try_from(value: i32) -> Result<Self, Self::Error> {
+        if value % 2 == 0 {
+            Ok(EvenNumber(value))
+        } else {
+            Err(())
+        }
+    }
+}
+
+fn main() {
+    assert_eq!(EvenNumber::try_from(8), Ok(EvenNumber(8)));
+    assert_eq!(EvenNumber::try_from(5), Err(()));
+
+    let result: Result<EvenNumber, ()> = 8i32.try_into();
+    assert_eq!(result, Ok(EvenNumber(8)));
+
+    let result: Result<EvenNumber, ()> = 5i32.try_into();
+    assert_eq!(result, Err(()));
+}