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  • Oct 10 2017 22:42
    @jpitts banned @etherchamp1_twitter
  • Jun 05 2016 10:33
    @chriseth banned @adamskee
chriseth
@chriseth:matrix.org
[m]
the payable(...) converts an address to an address payable
it means you are declaring that msg.sender can receive ether
贝克街的天才
@yuyenews
Record the creator when the contract is initialized
smrpn
@smrpn:matrix.org
[m]
okay, so here msg.sender is the address who is calling the contract?
贝克街的天才
@yuyenews
yes
smrpn
@smrpn:matrix.org
[m]
how do i get the address which deployed the contract?
i'm making a nft marketplace, and i want to transfer a percentage of the sale to the contract owner
chriseth
@chriseth:matrix.org
[m]
in the constructor, msg.sender is the deployer
贝克街的天才
@yuyenews
View the value of the owner variable of the contract on the block browser. If the contract was deployed by you, then the contract owner is the address of the wallet you used to deploy the contract.
1 reply
smrpn
@smrpn:matrix.org
[m]
ohhh
okay, how do I get this address in my solidity contract?
like, is there any way i can get that address using an inbuilt function?
贝克街的天才
@yuyenews
Not quite sure what you mean, are you trying to get the owner of another contract in your contract?
2 replies
贝克街的天才
@yuyenews
image.png
smrpn
@smrpn:matrix.org
[m]
thanks
George Carder
@georgercarder

(also asked in compiler channel and they referred me here)

  • in assembly what is the storage location of return data?

  • put directly.. given the example below, what is location?

thanks in advance

given

... in contract

modifier defer(... args ..) {
  _;
  // want to use assembly here to access return data of modified function
  // so I imagine it'd be like
  bytes memory returnPtr;
  assembly {
    returnPtr := mload(location)
  }
   <Type> returnData;
   (returnData) = abi.decode(returnPtr, <Type>);
  // DO STUFF
}

function someFunction() defer(..args..) {
  if (monday) {
    return 42;
  } else if (tuesday) {
    return 32;
  }
  return 123;
}
Br4ndonP0nce
@Br4ndonP0nce
Yo hey guys, im having a dumb problem probably, i cant assign a value to a key in a mapping, if i do it thru a function it works but if i want to do it as the result of an if confitional it just returns 0
Tadashi
@htadashi

Hey masters. Is this $$ a special keyword of solidity ?

  function setContract(CoreContracts name, address contractAddress) public {
        require(msg.sender == DIRECTORY, $$(ErrorCode(UNAUTHORIZED_CALLER)));  <- this is the line with the "$$"
        contracts[uint256(name)] = contractAddress;
    }

Found in this contract

Oh nvm. Just found out the answer... is a command for solpp, a solidity pre-processor
贝克街的天才
@yuyenews

HI, please ask a question, my project directory structure is like this, now I need to upload the source code to https://etherscan.io

But https://etherscan.io doesn't seem to support source code validation for this structure, it only supports single file source code and multiple file source code in the same directory, and my source code is multiple files in different directories.

Do you have any solution to this problem?

image.png
image.png
贝克街的天才
@yuyenews
Here you can only select multiple files in the same directory at once
Roney
@Roney16325329_twitter
melbourne2991
@melbourne2991
do unused arguments end up in the transaction log?
I basically want an additional piece of data to operate on externally of contract. I know I could use an event for this, but wondering if I could just add an extra arg as a cheaper alternative?
berktaylan
@berktaylan
hello everyone , im newly intrested with smart contracts , i got a theorical question ( not coding or development help ) anyone can help me to understand something i dont know about smart chains
rxx
@rxx:converser.eu
[m]
which is the ethereum space?
João Vitor Ianuci
@joaoianuci
Hello guys, I'm new on solidity contracts - I have a problem doing a contract with mint number of 20K unique nfts, How I can check that an ipfs metadata already minted, there a way without a large loop?
Moody Salem
@moodysalem
hey yall... is the solidity baked in safemath the cheapest implementation?
1 reply
i'm finding switching from our implementation to the builtin makes operations more gas expensive
in addition, it added 500 bytes of bytecode
Merouane B.
@cryptofact
Hi, i’m looking to batch mint NFTs with the optimal gas fees, NFTs have single copy of each. Should I use ERC 721 or 1155 to do so ?
chriseth
@chriseth:matrix.org
[m]
what did you ure before?
Richard Zhang
@rrzhang139
Hi guys, do you consider scaling contracts to multiple contracts (maybe Factory design)? I'm worried that storing data on 1 contract will be costly
Perelyn Sama
@Perelyn-sama
Hey does anyone have a way to create a react dapp? I tried the truffle react box but I'm getting some errors
Nikolay Toplev
@nikolaytoplev0306:matrix.org
[m]
Hi, everyone. I would be grateful for who can help me with triggering function call in solidity per block on binance smart chain. Thank you in advance.
Code Chef
@devofficer
Does anyone know how to trigger function calls per block in solidity?
2 replies
Nikolay Toplev
@nikolaytoplev0306:matrix.org
[m]
Could you offer me a link to show how to do that?
2 replies
shibatoshinakamoto
@shibatoshinakamoto:matrix.org
[m]
hello can someone help me understand why i cant withdraw my token
even tho the solidity code looks safe
tried all slippage
Jonathan Gros-Dubois
@jondubois
Does Ethereum support adding custom data to transactions?
If so, how many bytes in a transaction?
melvillian
@melvillian:one.ems.host
[m]

Yes, you can include it on the “data” field of the transaction. I’m not sure of the number of the bytes but the limit is probably not a problem, unless you’re trying to share something huuuge like video or image content. Don’t do that on Ethereum, use IPFS for that.

See this SO question, and you need to add the “data” field to the transaction

https://ethereum.stackexchange.com/questions/87683/trying-to-send-a-transaction-with-ethers-js

nobodyzees
@RudiHarss_twitter

Have you heard about the upcoming Bitcoin Bankathon? It's an international hackathon with five challenges to tackle real world problems by building decentralized financial applications. It lasts from November 19th till December 8th and contains a total of 250,000USD-equivalent prizes. If you want to sign up for it, please visit the website: https://bitcoin-alliance.org/

You can build with any language that compiles to the EVM. This includes Solidity, Julia, and new or experimental programming languages such as Vyper.

iemwill
@iemwill

First of all, thank you Vitalik Buterin !

@Perelyn-sama i would define a dApp, decentralized Application, by now and here, you just need one Component as a smartContract.

To really understand, what a smartContract is, we’ll need some good „openMic“-Sessions, or some defining content.. leacked

Unite.

scdev157
@scdev157
Hi Guys
For following contract, if I change B, would it change bytecode of contract ?
I was assuming that due to treeShaking it should not
but when I changed B, bytecode also changed
Can you please explain ?
bytes32 constant a = bytes32(hex"1e8e1b45c8500eaae36dbdda78698134042397867d83fedc92005af7c108c793");
bytes32 constant b = bytes32(hex"9723a2a3c9b49f62a314da557d9f0e080f0af927614758f525c253a9cfd1597a");

library Lib {
    function aaa() internal pure returns (bytes32) {
        return a;
    }

    function bbb() internal pure returns (bytes32) {
        return b;
    }
}

contract HelloWorld {
    function fn() external pure returns (bytes32) {
        return Lib.aaa();
    }
}
sharp2448
@sharp2448:matrix.org
[m]
Hi there!!
I asked question on OZ forum but nobody knows...
Is there somebody brave enough who would like to check it and perhaps collaborate?
I'm sure it will also help lots of devs in the future...
https://forum.openzeppelin.com/t/token-timelock-tips-caveats-etc/18404