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#[ink(constructor)]

Applicable to a method.

Flags a method (or multiple methods) for the ink! storage struct as constructor making it available to the API for instantiating the contract.

There must be at least one #[ink(constructor)] defined method.

Methods flagged with #[ink(constructor)] are special in that they are dispatchable upon contract instantiation. A contract may define multiple such constructors which allow users of the contract to instantiate a contract in multiple different ways.

Example#

use ink_lang as ink;
#[ink::contract]mod erc20 {    #[ink(storage)]    pub struct Erc20 { ... }
    impl Erc20 {        #[ink(constructor)]        pub fn new(initial_supply: Balance) -> Self { .. }
        #[ink(constructor)]        pub fn total_supply(&self) -> Balance { .. }
        // etc.    }}