文件 1 的 1:GDC.sol
pragma solidity ^0.5.0;
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
if (a == 0) {
return 0;
}
c = a * b;
assert(c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
c = a + b;
assert(c >= a);
return c;
}
}
contract GDCown {
address public owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
constructor() public {
owner = msg.sender;
}
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
function transferOwnership(address newOwner) public onlyOwner {
require(newOwner != address(0));
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
}
}
contract GDC20b {
function totalSupply() public view returns (uint256);
function balanceOf(address who) public view returns (uint256);
function transfer(address to, uint256 value) public returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
}
contract GDC20 is GDC20b {
function allowance(address owner, address spender) public view returns (uint256);
function transferFrom(address from, address to, uint256 value) public returns (bool);
function approve(address spender, uint256 value) public returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
contract GDCbasic is GDC20b {
using SafeMath for uint256;
mapping(address => uint256) balances;
uint256 totalSupply_;
function totalSupply() public view returns (uint256) {
return totalSupply_;
}
function transfer(address _to, uint256 _value) public returns (bool) {
require(_to != address(0));
require(_value <= balances[msg.sender]);
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}
function balanceOf(address _owner) public view returns (uint256) {
return balances[_owner];
}
}
contract GDCstandard is GDC20, GDCbasic {
mapping (address => mapping (address => uint256)) internal allowed;
function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
require(_to != address(0));
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
emit Transfer(_from, _to, _value);
return true;
}
function approve(address _spender, uint256 _value) public returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
function allowance(address _owner, address _spender) public view returns (uint256) {
return allowed[_owner][_spender];
}
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
}
contract GDC is GDCstandard, GDCown {
string public constant name = "Global Digital Currency Network";
string public constant symbol = "GDC";
uint32 public constant decimals = 18;
uint256 public constant tokenSupply = 1000000000*10**18;
constructor() public {
balances[owner] = balances[owner].add(tokenSupply);
totalSupply_ = totalSupply_.add(tokenSupply);
emit Transfer(address(this), owner, tokenSupply);
}
}
{
"compilationTarget": {
"GDC.sol": "GDC"
},
"evmVersion": "byzantium",
"libraries": {},
"optimizer": {
"enabled": false,
"runs": 200
},
"remappings": []
}