Questions tagged [library]
Libraries are reusable code. In the context of smart contracts, they are deployed only once at a specific address and their code is reused using DELEGATECALL.
0
votes
3answers
82 views
Ethereum Dapp Library
I would like to build Dapps on top of Ethereum and have a lot of ideas but the Solidity language is a bit difficult (at least to me). Is there a Windows library or a portable command line tool that ...
1
vote
2answers
92 views
Is library use inherited?
When a base class uses a library, do derived classes also use the same library?
For example:
contract A {
using SafeMath for uint256;
...
}
contract B is A {
//is code here using ...
1
vote
2answers
144 views
Publishing contracts with libraries using web3.py
Im trying to publish contracts with libraries in them and im getting the below issue. Contracts without libraries publish just fine. Can someone who might have faced this issue before advise what the ...
2
votes
1answer
134 views
Library function overloading
I have 3 libraries, one exposes struct and 2 others expose method with same signature/return type (first one provides default method implementation and second - extended and customized one). When ...
1
vote
1answer
22 views
Ethereum linking library with contract not working as accepted…returning any state variable returns just the default value
my library
pragma solidity ^0.5.8;
library SafeMath {
function add(uint256 a,uint256 b) public pure returns (uint256) {
return a+b;
}
}
My contract
pragma solidity ^0.5.8;
import ...
1
vote
1answer
144 views
Library function access-level
I have a contract A, which has an instance of contract B, i.e., B b.
Contract A calls a function of contract B via the instance, i.e., b.func().
Contract B is stateless, i.e., no global non-constant ...
1
vote
1answer
232 views
implement solidity library with no overhead of external function calls
When reading the doc of Solidity.I found out that the following is hard to understand or maybe I misunderstood something, any help is much appreciated.The document says:
The following example shows ...
0
votes
1answer
17 views
pass storage through interface to library
Here is what am i doing:
There is a library, accept storage argument as parameter, then do some math and return the result.
And there is a contract to call the function in the library, and an extra ...
0
votes
1answer
12 views
Link library to contract without migrations
To link library in migrations I use:
await deployer.deploy(MyTokenL)
await deployer.link(MyTokenL, MyToken)
We want to use migrations as infrastructure deployment and then have a deployment factory ...
0
votes
1answer
116 views
Contract libraries structure
I have pretty big smart contract with a lot of structs. Each struct has in average 3-4 related methods (i.e. methods with first parameter MyLibrary.MyType storage self).
Question about code ...
3
votes
0answers
194 views
Benefits of library versus a plain contract (upgradeability)
I'm trying to find what the benefit is of a library. I found the following statements. (Please correct me if i'm wrong)
Cost less gas to deploy
Uses the storage of the calling contract
the library ...
3
votes
0answers
183 views
What is the runtime performance of Ethereum Libraries compared to Contracts?
I'm looking for the cheapest way (in terms of gas price) to design upgradeable contracts. I don't expect many upgrades.
Being inspired by Writing upgradable contracts in Solidity, I'm investigating ...
2
votes
0answers
21 views
Can I import a Library from a Library?
Is it possible to import a library into another library?
I give a simplified example below of what I'd like to achieve:
library structLib {
struct Point {
uint X;
uint Y;
}
}
...
2
votes
0answers
88 views
Can I call a library function from a payable function?
I seem to get a revert each time I try this. I'm unable to get any useful revert message from truffle, so any assistance there might also help solve this.
I have a library:
library LibInterface {
....
2
votes
0answers
43 views
Which solidity dev environments support the use of already deployed library contracts?
So, I'm looking into using libraries in order to prevent re-deployment/re-use of the same code.
I was hoping that I would be able to specify the address of a library in solidity code, using syntax ...
2
votes
0answers
143 views
delegatecall on library always run out of gas
I'm trying to replicate the Dynamic Library attack of this paper under a recent version of solidity and the EVM.
Streamlining down the code, I've created this very simple contract (which is, in ...
2
votes
0answers
106 views
Solidity libraries with public visibility
Suppose I have the following Contracts and a Library:
pragma solidity ^0.4.21;
library UserLib {
function insertUser(address dbAddr, bytes32 user) public {
DB(dbAddr).setUser(user);
}
}
...
2
votes
0answers
193 views
How to create a contract B that calls a library via contract A
As I understand it, the logic to deploy contract that uses library is as below: supposed that MetaCoin contract use TestLib library
Deploy TestLib library first, then get a library contract address
...
2
votes
0answers
82 views
What's the value of `this` inside a library function when called via a delegatecall?
Imagine a contract C that makes a delegatecall to a library L.
C -> L
What's the value of this inside L: address(C) or address(L) ?
If now that L makes a normal call to another contract D.
C ->...
1
vote
0answers
40 views
Ethereum js wallet for php
https://github.com/ethereumjs/ethereumjs-wallet
I need this library with the same functions in PHP
Would u give me the link
1
vote
0answers
66 views
How to use delegate call with external Library contract?
Here is my Library Contract deployed at 0xdeadbeef:
library UsefulLib {
function caculateAddress(address origin, uint nonce)
pure
external
returns (address) {
if(nonce == 0x00)...
1
vote
0answers
45 views
Understanding Solidity Libraries using Solidity Docs code example
I was going through this code (see code below) about how to use libraries in solidity docs :
https://solidity.readthedocs.io/en/v0.4.24/contracts.html?highlight=library#libraries and there are some ...
1
vote
0answers
168 views
How to verify a contract with libraries deployed from Remix
I successfully deployed a contract with remix here on Ropsten Testnet:
https://ropsten.etherscan.io/address/0x10273a926517b417015748da21e1287bab2da8f7
The Source Code is very simple but I'm using my ...
1
vote
0answers
41 views
Can paritytech/parity be used as a library the same way that go-ethereum can be used in Go?
The go-ethereum project is divided into a set of standalone libraries that can be used in any Go project (e.g. smart contract interaction, keystore management, common cryptography and hex utils)
Can ...
0
votes
0answers
36 views
getting error error TypeError: Member “isContract” not found or not visible after argument-dependent lookup in address payable
Using Solidity 0.4.17, I have defined a simple library at ./Addresses.sol
function isContract(address _base) external pure returns(bool) {
assembly {
_r := gt(extcodesize(_base), 0)
...
