Chapter 1 excercises

chapter-1/.gitignore

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+/target
+**/*.rs.bk

chapter-1/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "chapter-1"
+version = "0.1.0"
+

chapter-1/Cargo.toml

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+[package]
+name = "chapter-1"
+version = "0.1.0"
+authors = ["Vladan Popovic <vladanovic@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

chapter-1/src/main.rs

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+fn id<T>(x: T) -> T {
+    x
+}
+
+fn compose<A, B, C, F, G>(f: F, g: G) -> impl Fn(A) -> C
+where
+    F: Fn(A) -> B,
+    G: Fn(B) -> C,
+{
+    move |x: A| g(f(x))
+}
+
+fn inc(x: u32) -> u32 {
+    x + 1
+}
+
+fn main() {
+    assert!(compose(id, inc)(2) == compose(inc, id)(2));
+}