Macro unconstrained

macro_rules! unconstrained {
    (  $($block:tt)* ) => { ... };
}

Executes a block of code unconstrained by the VM. This macro is useful for running code that helps provide information to the program but does not need to be constrained by the VM. For example, running ecrecover is expensive in the VM but verifying a signature when you know the public key is not. unconstrained can be used to provide the public key without spending VM CPU cycles.

Any changes to the VM state will be reset at the end of the block. To provide data to the VM, use io::hint or io::hint_slice, and read it using io::read or io::read_vec.