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Add note in ERC20Wrapper about rebasing tokens (#4755)

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Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>
This commit is contained in:
Ernesto García
2023-11-27 09:39:42 -06:00
committed by GitHub
parent 0b1b5f89ef
commit 769071d473
1 changed files with 7 additions and 2 deletions
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9
contracts/token/ERC20/extensions/ERC20Wrapper.sol
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@ -12,6 +12,11 @@ import {SafeERC20} from "../utils/SafeERC20.sol";
* Users can deposit and withdraw "underlying tokens" and receive a matching number of "wrapped tokens". This is useful
* in conjunction with other modules. For example, combining this wrapping mechanism with {ERC20Votes} will allow the
* wrapping of an existing "basic" ERC-20 into a governance token.
*
* WARNING: Any mechanism in which the underlying token changes the {balanceOf} of an account without an explicit transfer
* may desynchronize this contract's supply and its underlying balance. Please exercise caution when wrapping tokens that
* may undercollateralize the wrapper (i.e. wrapper's total supply is higher than its underlying balance). See {_recover}
* for recovering value accrued to the wrapper.
*/
abstract contract ERC20Wrapper is ERC20 {
IERC20 private immutable _underlying;
@ -75,8 +80,8 @@ abstract contract ERC20Wrapper is ERC20 {
}
/**
* @dev Mint wrapped token to cover any underlyingTokens that would have been transferred by mistake. Internal
* function that can be exposed with access control if desired.
* @dev Mint wrapped token to cover any underlyingTokens that would have been transferred by mistake or acquired from
* rebasing mechanisms. Internal function that can be exposed with access control if desired.
*/
function _recover(address account) internal virtual returns (uint256) {
uint256 value = _underlying.balanceOf(address(this)) - totalSupply();