Call address.transfer() with Gas Limit and Price from another function

Question

I have a smart contract where user can transfer ETH to an ICO. Like this

function buyICO(paymentAddress, amount) {

// do some other important things

// transfer the amount to the payment address
paymentAddress.transfer(amount);

}

Because some ICOs require a specific gas price and limit, but I can't set these in the transfer function. I can set it when user call buyICO() function but I don't know how do I calculate the gas limit and price for the whole thing.

What's the best practice here?

Answer 1

If you want to adjust gas limit you should use address.call.value().gas()(). See this answer for more details <address>.send vs <address>.transfer best practice usage? You can't adjust the gas price though.