Rust☆연습_Traits_part2

// Dungeons and Dragons
struct Dwarf {
    name: String,
}

struct Elf {
    name: String,
}

struct HalfElf {
    name: String,
}

struct HalfOrc {
    name: String,
}

struct Human {
    name: String,
}

impl Constitution for Elf {}
impl Constitution for Human {}

// The constitution bonus for a dwarf is 2
impl Constitution for Dwarf {
    fn constitution_bonus(&self) -> u8 {
        2
    }
}

impl Constitution for HalfOrc {
    fn constitution_bonus(&self) -> u8 {
        1
    }
}

pub trait Constitution {
    fn constitution_bonus(&self) -> u8 {
        0
    }
}

// Let's make a function for speaking Elvish
pub trait Elvish {}

impl Elvish for Elf {}
impl Elvish for HalfElf {}
impl Elvish for HalfOrc {}


pub fn speak_elvish<T: Elvish>(character: T) -> String {
    String::from("yes")
}

pub fn no_speak_elvish<T: Elvish>(character: T) -> String {
    String::from("no")
}

fn main() {
    let my_dwarf = Dwarf {
        name: String::from("NellDwarf"),
    };

    let my_elf = Elf {
        name: String::from("NellElf"),
    };

    let my_half_orc = HalfOrc {
        name: String::from("NellHalfOrc"),
    };

    let my_human = Human {
        name: String::from("NellHuman"),
    };

    let my_half_elf = HalfElf {
        name: String::from("NellElf"),
    };

    // Return 2
    my_dwarf.constitution_bonus();

    // Return 1
    dbg!(my_half_orc.constitution_bonus());

    // Return 0
    dbg!(my_elf.constitution_bonus());
    dbg!(my_human.constitution_bonus());

    // Return "yes"
    dbg!(speak_elvish(my_elf));

    // Return "yes"
    dbg!(speak_elvish(my_half_elf));

    // Return "yes"
    dbg!(no_speak_elvish(my_half_orc));
}

 

 

 

결과

 Compiling playground v0.0.1 (/playground)
warning: unused variable: `character`
  --> src/main.rs:52:32
   |
52 | pub fn speak_elvish<T: Elvish>(character: T) -> String {
   |                                ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_character`
   |
   = note: `#[warn(unused_variables)]` on by default

warning: unused variable: `character`
  --> src/main.rs:56:35
   |
56 | pub fn no_speak_elvish<T: Elvish>(character: T) -> String {
   |                                   ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_character`

warning: field `name` is never read
 --> src/main.rs:3:5
  |
2 | struct Dwarf {
  |        ----- field in this struct
3 |     name: String,
  |     ^^^^^^^^^^^^
  |
  = note: `#[warn(dead_code)]` on by default

warning: field `name` is never read
 --> src/main.rs:7:5
  |
6 | struct Elf {
  |        --- field in this struct
7 |     name: String,
  |     ^^^^^^^^^^^^

warning: field `name` is never read
  --> src/main.rs:11:5
   |
10 | struct HalfElf {
   |        ------- field in this struct
11 |     name: String,
   |     ^^^^^^^^^^^^

warning: field `name` is never read
  --> src/main.rs:15:5
   |
14 | struct HalfOrc {
   |        ------- field in this struct
15 |     name: String,
   |     ^^^^^^^^^^^^

warning: field `name` is never read
  --> src/main.rs:19:5
   |
18 | struct Human {
   |        ----- field in this struct
19 |     name: String,
   |     ^^^^^^^^^^^^

warning: `playground` (bin "playground") generated 7 warnings
    Finished dev [unoptimized + debuginfo] target(s) in 0.61s
     Running `target/debug/playground`
[src/main.rs:85] my_half_orc.constitution_bonus() = 1
[src/main.rs:88] my_elf.constitution_bonus() = 0
[src/main.rs:89] my_human.constitution_bonus() = 0
[src/main.rs:92] speak_elvish(my_elf) = "yes"
[src/main.rs:95] speak_elvish(my_half_elf) = "yes"
[src/main.rs:98] no_speak_elvish(my_half_orc) = "no"

 

 

 

 

 

한글러스트Rust강의_017_traits_기초 #rustlang #rust #traits

 

https://youtu.be/YNPFIVGBCjE

 

 

 

 

 

 

 

 

 

 

 

 

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