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authorBrandon Millman <brandon.millman@gmail.com>2018-02-06 05:16:46 +0800
committerBrandon Millman <brandon.millman@gmail.com>2018-02-06 05:16:46 +0800
commit99b1f81e89e3ac929c7829552ea7ae19998524e9 (patch)
tree534161a9fa8bcf8bb5572d7ef0aa311fe9b9d116 /packages/contracts/src/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
parent6577d607332e2fb1a442d663e260ecb969457c36 (diff)
parent46ad7b1b38df0f302821258629ffa749e7dd00b9 (diff)
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Merge branch 'development' into feature/testnet-faucets/order-dispenser
* development: (37 commits) Add dates to CHANGELOGs Change CHANGELOGs Add .editorconfig Fix a typo Temp Use forEach instead of map Add PR number Fix an exception when a signature collision happens Fix prettier Add regression tests Improve the comment and fix an exception Add missing comas Lerna-ignore tslint and tsconfig Update contract versions, fix tests Rename directories Rename previous contracts, fix imports, add nested file structure Move all contracts into a single directory Update import Fix import Get rid of suffixed contract versioning and replace it with a poor-mans package manager. Versions are stored locally, and are generated in a copy-on-write basis as required ...
Diffstat (limited to 'packages/contracts/src/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol')
-rw-r--r--packages/contracts/src/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol46
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diff --git a/packages/contracts/src/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol b/packages/contracts/src/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
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+++ b/packages/contracts/src/current/tokens/UnlimitedAllowanceToken/UnlimitedAllowanceToken.sol
@@ -0,0 +1,46 @@
+/*
+
+ Copyright 2017 ZeroEx Intl.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+*/
+
+pragma solidity ^0.4.18;
+
+import { ERC20Token } from "../ERC20Token/ERC20Token.sol";
+
+contract UnlimitedAllowanceToken is ERC20Token {
+
+ uint constant MAX_UINT = 2**256 - 1;
+
+ /// @dev ERC20 transferFrom, modified such that an allowance of MAX_UINT represents an unlimited allowance. See https://github.com/ethereum/EIPs/issues/717
+ /// @param _from Address to transfer from.
+ /// @param _to Address to transfer to.
+ /// @param _value Amount to transfer.
+ /// @return Success of transfer.
+ function transferFrom(address _from, address _to, uint _value)
+ public
+ returns (bool)
+ {
+ uint allowance = allowed[_from][msg.sender];
+ require(balances[_from] >= _value && allowance >= _value && balances[_to] + _value >= balances[_to]);
+ balances[_to] += _value;
+ balances[_from] -= _value;
+ if (allowance < MAX_UINT) {
+ allowed[_from][msg.sender] -= _value;
+ }
+ Transfer(_from, _to, _value);
+ return true;
+ }
+}