withdraw_gas

Withdraws gas from the GasBuiltin to handle the success case flow. Returns Some(()) if there is sufficient gas to handle the success case, otherwise returns None. # Examples

// The success branch is the following lines, the failure branch is the `panic` caused by the
// `unwrap` call.
withdraw_gas().unwrap();

// Direct handling of `withdraw_gas`.
match withdraw_gas() {
    Some(()) => success_case(),
    None => cheap_not_enough_gas_case(),
}

Fully qualified path: core::gas::withdraw_gas

pub extern fn withdraw_gas() -> Option<()> implicits(RangeCheck, GasBuiltin) nopanic;