ERC-20 可销毁

ERC-20 的扩展，允许 token 持有者销毁他们自己的 token 以及他们具有授权的 token，这种方式可以通过链下识别（通过事件分析）。

用法

为了使 ERC-20 Burnable 方法成为 “external”，以便其他合约可以调用它们，你需要为你最终的合约自行实现它们，如下所示：

use openzeppelin_stylus::token::erc20::{
    self, extensions::IErc20Burnable, Erc20, IErc20,
};

#[entrypoint]
#[storage]
struct Erc20Example {
    erc20: Erc20,
}

#[public]
#[implements(IErc20<Error = erc20::Error>, IErc20Burnable<Error = erc20::Error>)]
impl Erc20Example {}


#[public]
impl IErc20 for Erc20Example {
    type Error = erc20::Error;

    fn total_supply(&self) -> U256 {
        self.erc20.total_supply()
    }

    fn balance_of(&self, account: Address) -> U256 {
        self.erc20.balance_of(account)
    }

    fn transfer(
        &mut self,
        to: Address,
        value: U256,
    ) -> Result<bool, Self::Error> {
        self.erc20.transfer(to, value)
    }

    fn allowance(&self, owner: Address, spender: Address) -> U256 {
        self.erc20.allowance(owner, spender)
    }

    fn approve(
        &mut self,
        spender: Address,
        value: U256,
    ) -> Result<bool, Self::Error> {
        self.erc20.approve(spender, value)
    }

    fn transfer_from(
        &mut self,
        from: Address,
        to: Address,
        value: U256,
    ) -> Result<bool, Self::Error> {
        self.erc20.transfer_from(from, to, value)
    }
}


#[public]
impl IErc20Burnable for Erc20Example {
    type Error = erc20::Error;

    fn burn(&mut self, value: U256) -> Result<(), erc20::Error> {
        // ...
        self.erc20.burn(value)
    }

    fn burn_from(
        &mut self,
        account: Address,
        value: U256,
    ) -> Result<(), erc20::Error> {
        // ...
        self.erc20.burn_from(account, value)
    }
}