types.plk

struct Pair<A, B> {
    first: A,
    second: B,
}

struct PairOfInts {
    i: i32,
    j: i32,
}

fn print_num(num: u32) {
    if num >= 10 {
        print_num(num / 10);
    }
    putc('0' + ((num % 10) as Pair<u8, u16>).first);
}

fn print(mut msg: *u8) {
    while *msg != 0 {
        putc(*msg);
        msg = (msg as u32 + 1) as *u8;
    }
}

fn print_size<T>(name: *u8) {
    print("size_of::<");
    print(name);
    print(">() = ");
    print_num(size_of::<T>());
    putc('\n');
}

fn main() -> i32 {
    // numeric types
    print_size::<u8>("u8");
    print_size::<i8>("i8");
    print_size::<u16>("u16");
    print_size::<i16>("i16");
    print_size::<u32>("u32");
    print_size::<i32>("i32");

    // bool
    print_size::<bool>("bool");

    // unit - a zero sized type with value also called `unit`.
    // functions that do not have a specified return type return unit
    print_size::<unit>("unit");

    // pointers and function pointers
    print_size::<*u8>("*u8");
    print_size::<*Pair<u8, u32>>("*Pair<u8, u32>");
    print_size::<fn(u8) -> i32>("fn(u8) -> i32");

    // structs
    print_size::<PairOfInts>("PairOfInts");

    // generic structs
    print_size::<Pair<u8, u8>>("Pair<u8, u8>");
    print_size::<Pair<i32, *u8>>("Pair<i32, *u8>");

    return 0;
}