Struct PassPointerAndReadCopy

pub struct PassPointerAndReadCopy<T, const N: usize>(/* private fields */);

Pass a value into the host by a thin pointer.

This casts the value into a &[u8] using AsRef<[u8]> and passes a pointer to that byte blob to the host. Then the host reads N bytes from that address into an [u8; N], converts it into target type using From<[u8; N]> and passes it into the host function by a copy.

Use PassPointerAndRead if you want to have the host function accept a reference type on the host side or if you’d like to avoid the extra copy.

Raw FFI type: u32 (a pointer)

Trait Implementations

impl<'a, T, const N: usize> FromFFIValue<'a> for PassPointerAndReadCopy<T, N>

where T: From<[u8; N]> + Copy,

type Owned = 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, const N: usize> RIType for PassPointerAndReadCopy<T, N>

type FFIType = u32

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.