Library.md

Solidity Library

Library 특징

• No state variables
• Cannot inherit nor be inherited
• Cannot receive Ether
• 선언
  • library Name { code }
• 사용
  • using Name for uint256; // type
  • using Name for *; // wildcard type
• https://solidity.readthedocs.io/en/v0.4.24/contracts.html#libraries

Library 예제

• safeMath https://github.com/solidity-korea/solidity-A-to-Z/blob/master/contracts/OverflowUnderflow.sol
  • internal, private function 으로 구성된 Library 는 통합 배포됨
• MathUtils 올림, 내림, 반올림 Library 예제
  • https://github.com/solidity-korea/solidity-A-to-Z/blob/master/contracts/LibTest.sol
  • public, external function 으로 구성된 Library 는 통합 별도 배포, link 필요

Library Deploy, Verify

• remix, MetaMask, Etherscan
• solc, myCrypto, MEW 를 통한 배포
  • solc 설치 https://solidity.readthedocs.io/en/v0.4.24/installing-solidity.html#binary-packages

Library Link using solc

• solc --bin LibTest.sol
• solc --bin LibTest.sol | solc --link --libraries LibTest.sol:MathUtils:0x95816bd09ce1ac416f2d07a7e2d2dbbbf17b9337
• solc --bin LibTest.sol --libraries LibTest.sol:MathUtils:0x95816bd09ce1ac416f2d07a7e2d2dbbbf17b9337
• https://solidity.readthedocs.io/en/v0.4.24/using-the-compiler.html

usages

• https://solidity.readthedocs.io/en/v0.4.24/contracts.html#libraries