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5. ink! 5.0: Rust Smart Contracts

Wasm and RISC-V on-chain smart contracts.

1 min read2 questionsup to 50 XPtopic 5/5

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ink! is a Rust embedded domain-specific language (eDSL) targeting WebAssembly (`pallet_contracts`) and Polkadot Revive (RISC-V). ink! 5.0 provides memory-efficient cross-contract calls, constructor return flags, and e2e testing.

rust
#[ink::contract]
mod flipper {
    #[ink(storage)]
    pub struct Flipper {
        value: bool,
    }

    impl Flipper {
        #[ink(constructor)]
        pub fn new(init_value: bool) -> Self {
            Self { value: init_value }
        }

        #[ink(message)]
        pub fn flip(&mut self) {
            self.value = !self.value;
        }
    }
}

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Check your understanding

1. What engine executes ink! smart contracts on Substrate chains?
pallet_contracts (Wasm / Revive)EVM onlyLinux kernelNode.js
2. What attribute designates a public state-mutating function in ink!?
#[ink(message)]#[ink(constructor)]#[ink(storage)]#[ink(event)]

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