Trait DispatchableConstructorInfo

Source

pub trait DispatchableConstructorInfo<const ID: u32> {
    type Input;
    type Storage;
    type Output;
    type Error;

    const IS_RESULT: bool;
    const CALLABLE: fn(Self::Input) -> Self::Output;
    const DECODE: fn(&mut &[u8]) -> Result<Self::Input, DispatchError>;
    const RETURN: fn(ReturnFlags, Result<(), &Self::Error>);
    const PAYABLE: bool;
    const SELECTOR: Option<[u8; 4]>;
    const LABEL: &'static str;
    const ABI: Abi;
}

Expand description

Stores various information of the respective dispatchable ink! constructor.

§Note

This trait is implemented by ink! for every dispatchable ink! constructor of the root ink! smart contract. The ID used in the trait reflects the chosen or derived selector of the dispatchable ink! constructor.

§Usage


#[ink::contract]
pub mod contract {
    #[ink(storage)]
    pub struct Contract {}

    impl Contract {
        #[ink(constructor)]
        pub fn constructor1() -> Self {
            Contract {}
        }

        #[ink(constructor, selector = 0xC0DECAFE)]
        pub fn constructor2(input1: i32, input2: i64) -> Self {
            Contract {}
        }

        #[ink(message)]
        pub fn message(&self) {}
    }
}

use contract::Contract;

/// Asserts that the constructor with the selector `ID` has the following properties.
///
/// # Note
///
/// The `In` and `Out` generic parameters describe the input and output types.
fn assert_constructor_info<In, const ID: u32>(selector: [u8; 4], label: &str)
where
    Contract: DispatchableConstructorInfo<{ ID }, Input = In>,
{
    assert_eq!(
        <Contract as DispatchableConstructorInfo<{ ID }>>::SELECTOR,
        Some(selector),
    );
    assert_eq!(
        <Contract as DispatchableConstructorInfo<{ ID }>>::LABEL,
        label,
    );
}

fn main() {
    assert_constructor_info::<(), { selector_id!("constructor1") }>(
        selector_bytes!("constructor1"),
        "constructor1",
    );
    assert_constructor_info::<(i32, i64), 0xC0DECAFE_u32>(
        [0xC0, 0xDE, 0xCA, 0xFE],
        "constructor2",
    );
}