Macro dilib::add_singleton_trait

macro_rules! add_singleton_trait {
    ($container:ident, $trait_type:ident $(<$($generic:ident),+>)? => $impl_expr:expr) => { ... };
    ($container:ident, $name:literal, $trait_type:ident $(<$($generic:ident),+>)? => $impl_expr:expr) => { ... };
    ($container:ident, $trait_type:ident $(<$($generic:ident),+>)? => { $impl_expr:expr }) => { ... };
    ($container:ident, $name:literal, $trait_type:ident $(<$($generic:ident),+>)? => { $impl_expr:expr }) => { ... };
    ($container:ident, $trait_type:ident $(<$($generic:ident),+>)? @ $inject_type:ty) => { ... };
    ($container:ident, $name:literal, $trait_type:ident $(<$($generic:ident),+>)? @ $inject_type:ty) => { ... };
}

Helper macro to bind a trait to it’s implementation in a Container as a singleton.

Overloads

add_singleton_trait!(container, name, trait => implementation) add_singleton_trait!(container, trait => implementation) add_singleton_trait!(container, name, trait @ Inject) add_singleton_trait!(container, trait @ Inject)

Params

• container: identifier of the container to add the implementation.
• name: optional name to store the provider.
• trait: the type of the trait.
• implementation: the implementation of the trait.
• Inject: a struct that implements Inject.

Examples

Basic usage

#[macro_use]
extern crate dilib;
use dilib::*;

trait Greet {
   fn greet(&self) -> &str;
}

struct HelloWorld;
impl Greet for HelloWorld {
  fn greet(&self) -> &'static str {
        "hello world"
    }
}

fn main() {
    let mut container = Container::new();
    add_singleton_trait!(container, Greet => HelloWorld).unwrap();

    let greet = get_singleton_trait!(container, Greet).unwrap();
    assert_eq!(greet.greet(), "hello world");
}

With named trait

#[macro_use]
extern crate dilib;
use dilib::*;

trait BinaryOp {
    fn calc(&self, lhs: i32, rhs: i32) -> i32;
}

struct Sum;
struct Prod;

impl BinaryOp for Sum {
    fn calc(&self, lhs: i32, rhs: i32) -> i32 { lhs + rhs }
}

impl BinaryOp for Prod {
    fn calc(&self, lhs: i32, rhs: i32) -> i32 { lhs * rhs }
}

fn main() {
    let mut container = Container::new();
    add_singleton_trait!(container, "sum", BinaryOp => Sum).unwrap();
    add_singleton_trait!(container, "prod", BinaryOp => Prod).unwrap();

    let sum = get_singleton_trait!(container, BinaryOp, "sum").unwrap();
    let prod = get_singleton_trait!(container, BinaryOp, "prod").unwrap();

    assert_eq!(5, sum.calc(2, 3));
    assert_eq!(6, prod.calc(3, 2));
}