ERC20Minimal
Authors: Axicon Labs Limited, Modified from Solmate (https://github.com/transmissions11/solmate/blob/v7/src/tokens/ERC20.sol)
The metadata must be set in the inheriting contract.
Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
State Variables
totalSupply
The total supply of tokens.
This cannot exceed the max uint256 value.
uint256 public totalSupply;
balanceOf
Token balances for each user
mapping(address account => uint256 balance) public balanceOf;
allowance
Stored allowances for each user.
Indexed by owner, then by spender.
mapping(address owner => mapping(address spender => uint256 allowance)) public allowance;
Functions
approve
Approves a user to spend tokens on the caller's behalf.
function approve(address spender, uint256 amount) public returns (bool);
Parameters
| Name | Type | Description |
|---|---|---|
spender | address | The user to approve |
amount | uint256 | The amount of tokens to approve |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bool | Whether the approval succeeded |
transfer
Transfers tokens from the caller to another user.
function transfer(address to, uint256 amount) public virtual returns (bool);
Parameters
| Name | Type | Description |
|---|---|---|
to | address | The user to transfer tokens to |
amount | uint256 | The amount of tokens to transfer |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bool | Whether the transfer succeeded |
transferFrom
Transfers tokens from one user to another.
Supports token approvals.
function transferFrom(address from, address to, uint256 amount) public virtual returns (bool);
Parameters
| Name | Type | Description |
|---|---|---|
from | address | The user to transfer tokens from |
to | address | The user to transfer tokens to |
amount | uint256 | The amount of tokens to transfer |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bool | Whether the transfer succeeded |
_transferFrom
Internal utility to transfer tokens from one user to another.
function _transferFrom(address from, address to, uint256 amount) internal;
Parameters
| Name | Type | Description |
|---|---|---|
from | address | The user to transfer tokens from |
to | address | The user to transfer tokens to |
amount | uint256 | The amount of tokens to transfer |
_mint
Internal utility to mint tokens to a user's account.
function _mint(address to, uint256 amount) internal;
Parameters
| Name | Type | Description |
|---|---|---|
to | address | The user to mint tokens to |
amount | uint256 | The amount of tokens to mint |
_burn
Internal utility to burn tokens from a user's account.
function _burn(address from, uint256 amount) internal;
Parameters
| Name | Type | Description |
|---|---|---|
from | address | The user to burn tokens from |
amount | uint256 | The amount of tokens to burn |
Events
Transfer
Emitted when tokens are transferred
event Transfer(address indexed from, address indexed to, uint256 amount);
Parameters
| Name | Type | Description |
|---|---|---|
from | address | The sender of the tokens |
to | address | The recipient of the tokens |
amount | uint256 | The amount of tokens transferred |
Approval
Emitted when a user approves another user to spend tokens on their behalf
event Approval(address indexed owner, address indexed spender, uint256 amount);
Parameters
| Name | Type | Description |
|---|---|---|
owner | address | The user who approved the spender |
spender | address | The user who was approved to spend tokens |
amount | uint256 | The amount of tokens approved to spend |