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OptimismL2StandardERC20

OptimismL2StandardERC20#

Functions#

constructor(string name_, string symbol_) (public)

Sets the values for {name} and {symbol}. The default value of {decimals} is 18. To select a different value for {decimals} you should overload it. All two of these values are immutable: they can only be set once during construction.

name() → string (public)

Returns the name of the token.

symbol() → string (public)

Returns the symbol of the token, usually a shorter version of the name.

decimals() → uint8 (public)

Returns the number of decimals used to get its user representation. For example, if decimals equals 2, a balance of 505 tokens should be displayed to a user as 5.05 (505 / 10 ** 2). Tokens usually opt for a value of 18, imitating the relationship between Ether and Wei. This is the value {ERC20} uses, unless this function is overridden; NOTE: This information is only used for display purposes: it in no way affects any of the arithmetic of the contract, including {IERC20-balanceOf} and {IERC20-transfer}.

totalSupply() → uint256 (public)

See {IERC20-totalSupply}.

balanceOf(address account) → uint256 (public)

See {IERC20-balanceOf}.

transfer(address recipient, uint256 amount) → bool (public)

See {IERC20-transfer}. Requirements:

  • recipient cannot be the zero address.
  • the caller must have a balance of at least amount.
allowance(address owner, address spender) → uint256 (public)

See {IERC20-allowance}.

approve(address spender, uint256 amount) → bool (public)

See {IERC20-approve}. Requirements:

  • spender cannot be the zero address.
transferFrom(address sender, address recipient, uint256 amount) → bool (public)

See {IERC20-transferFrom}. Emits an {Approval} event indicating the updated allowance. This is not required by the EIP. See the note at the beginning of {ERC20}. Requirements:

  • sender and recipient cannot be the zero address.
  • sender must have a balance of at least amount.
  • the caller must have allowance for sender's tokens of at least amount.
increaseAllowance(address spender, uint256 addedValue) → bool (public)

Atomically increases the allowance granted to spender by the caller. This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}. Emits an {Approval} event indicating the updated allowance. Requirements:

  • spender cannot be the zero address.
decreaseAllowance(address spender, uint256 subtractedValue) → bool (public)

Atomically decreases the allowance granted to spender by the caller. This is an alternative to {approve} that can be used as a mitigation for problems described in {IERC20-approve}. Emits an {Approval} event indicating the updated allowance. Requirements:

  • spender cannot be the zero address.
  • spender must have allowance for the caller of at least subtractedValue.
_transfer(address sender, address recipient, uint256 amount) (internal)

Moves amount of tokens from sender to recipient. This internal function is equivalent to {transfer}, and can be used to e.g. implement automatic token fees, slashing mechanisms, etc. Emits a {Transfer} event. Requirements:

  • sender cannot be the zero address.
  • recipient cannot be the zero address.
  • sender must have a balance of at least amount.
_mint(address account, uint256 amount) (internal)

Creates amount tokens and assigns them to account, increasing the total supply. Emits a {Transfer} event with from set to the zero address. Requirements:

  • account cannot be the zero address.
_burn(address account, uint256 amount) (internal)

Destroys amount tokens from account, reducing the total supply. Emits a {Transfer} event with to set to the zero address. Requirements:

  • account cannot be the zero address.
  • account must have at least amount tokens.
_approve(address owner, address spender, uint256 amount) (internal)

Sets amount as the allowance of spender over the owner s tokens. This internal function is equivalent to approve, and can be used to e.g. set automatic allowances for certain subsystems, etc. Emits an {Approval} event. Requirements:

  • owner cannot be the zero address.
  • spender cannot be the zero address.
_beforeTokenTransfer(address from, address to, uint256 amount) (internal)

Hook that is called before any transfer of tokens. This includes minting and burning. Calling conditions:

  • when from and to are both non-zero, amount of from's tokens will be transferred to to.
  • when from is zero, amount tokens will be minted for to.
  • when to is zero, amount of from's tokens will be burned.
  • from and to are never both zero. To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
_afterTokenTransfer(address from, address to, uint256 amount) (internal)

Hook that is called after any transfer of tokens. This includes minting and burning. Calling conditions:

  • when from and to are both non-zero, amount of from's tokens has been transferred to to.
  • when from is zero, amount tokens have been minted for to.
  • when to is zero, amount of from's tokens have been burned.
  • from and to are never both zero. To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
_msgSender() → address (internal)
_msgData() → bytes (internal)

Events#

Transfer(address from, address to, uint256 value)

Emitted when value tokens are moved from one account (from) to another (to). Note that value may be zero.

Approval(address owner, address spender, uint256 value)

Emitted when the allowance of a spender for an owner is set by a call to {approve}. value is the new allowance.