0xaf5d...e190

Utility

0xaf5d0d115d89...0f39db7ce190

Tangerine WhistleExact Bytecode MatchEdit this contract

Deployed November 2, 2016 (9 years ago)Block 2,555,234

Event emitter library for the Devcon 2 attendee token

Tangerine Whistle EraVerified Source

Historical Significance

A non fungible token event interface written more than a year before ERC-721 was proposed. The source comment points at solidity issue 1215, which is why the events live in a library at all.

Context

Deployed in the Homestead era, two months after Devcon 2 in Shanghai.

Key Facts

Deployer

Piper Merriam(0xd3cda9...293601)

Deployment Block

2,555,234

Deployment Date

Nov 2, 2016, 10:02 PM

Code Size

212.0 B

Deployment Transaction: 0x39f346479e1cb47a...7b1a7ec723981688

Description

TokenEventLib exists so that a token contract can emit Transfer and Approval events from library code, which Solidity could not do directly at the time. The events carry a bytes32 token identifier rather than an amount, because the Devcon 2 token gives each attendee a distinct token instead of a divisible balance. Deployed on 2 November 2016 by 0xd3cda913deb6f67967b99d67acdfa1712c293601, the account of Piper Merriam, and recovered from pipermerriam/devcon2-token.

Source Verified

Exact bytecode match(212 bytes)

Compiler: v0.4.2+

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Heuristic Analysis

The following characteristics were detected through bytecode analysis and may not be accurate.

Detected Type: Utility

Tangerine Whistle Era

Emergency fork to address DoS attacks. Repriced IO-heavy opcodes.

Block span: 2,463,000 — 2,674,999

October 18, 2016 — November 22, 2016

Bytecode Overview

Opcodes212

Unique Opcodes87

Jump Instructions11

Storage Operations2

Verified Source Available

Source verified through compiler archaeology and exact bytecode matching.

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Show source code (Solidity)

// Submitted by EthereumHistory (ethereumhistory.com)
pragma solidity ^0.4.0;


library TokenEventLib {
    /*
     * When underlying solidity issue is fixed this library will not be needed.
     * https://github.com/ethereum/solidity/issues/1215
     */
    event Transfer(address indexed _from,
                   address indexed _to,
                   bytes32 indexed _tokenID);
    event Approval(address indexed _owner,
                   address indexed _spender,
                   bytes32 indexed _tokenID);

    function _Transfer(address _from, address _to, bytes32 _tokenID) public {
        Transfer(_from, _to, _tokenID);
    }

    function _Approval(address _owner, address _spender, bytes32 _tokenID) public {
        Approval(_owner, _spender, _tokenID);
    }
}