shapely-core 3.1.0

#![warn(missing_docs)]
#![doc = include_str!("../README.md")]

use std::mem::MaybeUninit;

mod impls;

mod scalar_contents;
pub use scalar_contents::ScalarContents;

mod shape;
pub use shape::*;

mod slot;
pub use slot::Slot;

mod partial;
pub use partial::*;

mod helpers;
pub use helpers::*;

pub mod mini_typeid;

#[doc(hidden)]
pub mod log;
pub use log::*;

#[cfg(test)]
mod tests;

/// A wrapper around `Vec<u8>` for binary data
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Bytes(pub Vec<u8>);

impl Shapely for Bytes {
    fn shape() -> Shape {
        Shape {
            name: |f, _opts| write!(f, "Bytes"),
            typeid: mini_typeid::of::<Self>(),
            layout: std::alloc::Layout::new::<Self>(),
            innards: Innards::Scalar(Scalar::Bytes),
            set_to_default: Some(|addr: *mut u8| unsafe {
                *(addr as *mut Bytes) = Bytes(Vec::new());
            }),
            drop_in_place: Some(|addr: *mut u8| unsafe {
                std::ptr::drop_in_place(addr as *mut Bytes);
            }),
        }
    }
}

/// Allows querying the [Shape] of a type, which in turn lets us inspect any fields, build a value of
/// this type progressively, etc.
pub trait Shapely: Sized {
    /// Returns the shape of this type
    fn shape() -> Shape;

    /// Returns a shape def (a function that can describe this shape)
    fn shape_desc() -> ShapeDesc {
        ShapeDesc(Self::shape)
    }

    /// Allocates this shape on the heap and return a partial that allows gradually initializing its fields.
    fn partial() -> Partial<'static> {
        Partial::alloc(Self::shape_desc())
    }

    /// Initializes a `Partial` from a borrowed `MaybeUninit<Self>`.
    ///
    /// Before calling assume_init, make sure to call Partial.build_in_place().
    fn partial_from_uninit(dest: &mut MaybeUninit<Self>) -> Partial<'_> {
        Partial::borrow(dest)
    }

    // TODO: partial_from_mut? where all the fields are already initialized?
}