openzeppelin-contracts/contracts/token/SafeERC20.sol

pragma solidity ^0.4.11;

import './ERC20Basic.sol';
import './ERC20.sol';

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure.
 */
library SafeERC20 {
  function safeTransfer(ERC20Basic token, address to, uint256 value) internal {
    assert(token.transfer(to, value));
  }

  function safeTransferFrom(ERC20 token, address from, address to, uint256 value) internal {
    assert(token.transferFrom(from, to, value));
  }

  function safeApprove(ERC20 token, address spender, uint256 value) internal {
    assert(token.approve(spender, value));
  }
}