Function hdk::prelude::host_call

pub fn host_call<I, O>(
    f: unsafe extern "C" fn(_: u32, _: u32) -> u64,
    input: I
) -> Result<O, WasmError>where
    I: Serialize + Debug,
    O: DeserializeOwned + Debug,

Given an extern that we expect the host to provide:

• Serialize the payload by reference
• Write the bytes into a new allocation on the guest side
• Call the host function and pass it the pointer and length to our leaked serialized data
• The host will consume and deallocate the bytes
• Deserialize whatever bytes we can import from the host after calling the host function
• Return a Result of the deserialized output type O