Adding variadic fns

src/lib.rs

@@ -47,6 +47,7 @@ mod traits_return_impl; // todo: incomplete
 mod traits_same_name_fn_call;
 mod traits_supertraits;
 mod utils;
+mod variadic;
 
 // re-exports
 use crate::utils::print_type_of;

src/temp.rs

@@ -4,3 +4,4 @@
 // fn ex1_ww() {
 //     assert_eq!(32, 32);
 // }
+

src/variadic.rs

@@ -0,0 +1,55 @@
+
+/* 
+//// C++ variadic template sum
+#include <iostream>
+
+// C++17
+template<typename... Args>
+auto sum(Args... args)
+{
+    return (args + ...);
+}
+
+int main() {
+    std::cout << sum(1, 4.5) << std::endl;;	  // 5.5 !!  // diff. types
+    std::cout << sum(1, 4, 6) << std::endl;;
+
+    return 0;
+} 
+*/
+
+use std::fmt::Debug;
+
+struct Number { x: i32 }
+struct Text { y: String }
+
+enum Color {
+    Num(Number), 
+    Txt(Text)
+}
+
+fn variadic_generic(args: &[impl Debug]) {
+    for arg in args { println!("arg: {:?}", arg); }
+}
+
+fn variadic(args: &[Color]) {
+    if let Color::Num(n) = &args[0] {
+        println!("n.x: {:?}", n.x);
+    };
+    if let Color::Txt(t) = &args[1] {
+        println!("t.y: {:?}", t.y);
+    };
+}
+
+#[test]
+fn ex1() {
+    variadic(&[ 
+        Color::Num( Number{ x: 42 } ),
+        Color::Txt( Text{ y:"green".to_string() } ) 
+    ]);
+
+    variadic_generic(&[1, 2, 3]);
+    variadic_generic(&['a', 'b']);
+
+    assert_eq!(32, 32);
+}