Struct PassFatPointerAndDecode

pub struct PassFatPointerAndDecode<T>(/* private fields */);

Pass a T into the host using the SCALE codec.

This encodes a T into a Vec<u8> using the SCALE codec and then passes a pointer to that byte blob and its length to the host, which then reads it and decodes back into T.

Raw FFI type: u64 (a fat pointer; upper 32 bits is the size, lower 32 bits is the pointer)

Trait Implementations

impl<'a, T: Decode> FromFFIValue<'a> for PassFatPointerAndDecode<T>

type Owned = Option<T>

The owned inner type.

fn from_ffi_value( context: &mut dyn FunctionContext, arg: Self::FFIType, ) -> Result<Self::Owned>

Creates Self::Owned from the given arg received through the FFI boundary from the runtime.

fn take_from_owned(owned: &'a mut Self::Owned) -> Self::Inner

Creates Self::Inner from an owned value.

fn write_back_into_runtime( _value: Self::Owned, _context: &mut dyn FunctionContext, _arg: Self::FFIType, ) -> Result<()>

Write back a modified value back into the runtime’s memory.

impl<T> RIType for PassFatPointerAndDecode<T>

type FFIType = u64

The raw FFI type that is used to pass Self through the host <-> runtime boundary.

type Inner = T

The inner type without any serialization strategy wrapper.