msg.value & payable functions

Payable functions

Say you want to make a call to another contract's payable function and transfer ETH:

targetAddress.someFunction{ value: amount }(arg1, arg2, arg3)

• calls someFunction on targetAddress contract

• sends amount of ETH

• this works if someFunction is a payable function

Calling payable functions

WETH.sol

function deposit() public payable {
    balanceOf[msg.sender] += msg.value;
    emit Deposit(msg.sender, msg.value);
}

Vault.sol

weth.deposit{value: 1 ether}();

• From Vault, we call the payable function deposit, and pass msg.value within the value field

• https://ethereum.stackexchange.com/questions/60279/how-to-set-msg-value-in-solidity-function-call