1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66

//! See [`Library`].
 
use crate::auxlib::Reg;
use crate::cdef::CFunction;

use core::ffi::CStr;
use core::marker::PhantomData;
use core::mem::{
	transmute, MaybeUninit
};
use core::ptr::null;
use core::slice::from_raw_parts;

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
#[repr(C)]
pub struct Library<'name, const N: usize> {
	pub regs: [Reg; N],
	terminator: Reg,
	_life: PhantomData<&'name CStr>
}

impl<'name, const N: usize> Library<'name, N> {
	pub const fn new(
		items: [(&'name CStr, CFunction); N]
	) -> Self {
		// SAFETY: We make an uninit `[Reg; N]`, but then immediately fill it
		// with stuff without reading from it.
		let regs: [Reg; N] = unsafe {
			let mut dest: [Reg; N] = MaybeUninit::uninit().assume_init();
	
			let mut i = 0;
			while i < N {
				dest[i] = Reg {
					name: items[i].0.as_ptr(),
					func: Some(items[i].1)
				};
				i += 1;
			}

			dest
		};

		Self {
			regs,
			terminator: Reg {
				name: null(),
				func: None
			},
			_life: PhantomData
		}
	}

	pub const fn ffi_len() -> usize {
		N + 1
	}

	pub const fn as_ptr(&self) -> *const Reg {
		unsafe { transmute(self as *const _) }
	}

	pub const fn as_reg_slice(&self) -> &[Reg] {
		unsafe { from_raw_parts(
			transmute(self as *const _ as *const Reg), N + 1
		) }
	}
}