1 use crate::marker::Destruct;
3 /// Struct representing a closure with mutably borrowed data.
7 /// #![feature(const_mut_refs)]
8 /// use crate::const_closure::ConstFnMutClosure;
9 /// const fn imp(state: &mut i32, (arg,): (i32,)) -> i32 {
14 /// let mut cl = ConstFnMutClosure::new(&mut i, imp);
16 /// assert!(7 == cl(2));
17 /// assert!(8 == cl(1));
19 pub(crate) struct ConstFnMutClosure<CapturedData, Function> {
20 /// The Data captured by the Closure.
21 /// Must be either a (mutable) reference or a tuple of (mutable) references.
22 pub data: CapturedData,
23 /// The Function of the Closure, must be: Fn(CapturedData, ClosureArgs) -> ClosureReturn
26 impl<'a, CapturedData: ?Sized, Function> ConstFnMutClosure<&'a mut CapturedData, Function> {
27 /// Function for creating a new closure.
29 /// `data` is the a mutable borrow of data that is captured from the environment.
30 /// If you want Data to be a tuple of mutable Borrows, the struct must be constructed manually.
32 /// `func` is the function of the closure, it gets the data and a tuple of the arguments closure
33 /// and return the return value of the closure.
34 pub(crate) const fn new<ClosureArguments, ClosureReturnValue>(
35 data: &'a mut CapturedData,
39 Function: ~const Fn(&mut CapturedData, ClosureArguments) -> ClosureReturnValue,
45 macro_rules! impl_fn_mut_tuple {
47 #[allow(unused_parens)]
48 impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const
49 FnOnce<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function>
51 Function: ~const Fn(($(&mut $var),*), ClosureArguments) -> ClosureReturnValue+ ~const Destruct,
53 type Output = ClosureReturnValue;
55 extern "rust-call" fn call_once(mut self, args: ClosureArguments) -> Self::Output {
59 #[allow(unused_parens)]
60 impl<'a, $($var,)* ClosureArguments, Function, ClosureReturnValue> const
61 FnMut<ClosureArguments> for ConstFnMutClosure<($(&'a mut $var),*), Function>
63 Function: ~const Fn(($(&mut $var),*), ClosureArguments)-> ClosureReturnValue,
65 extern "rust-call" fn call_mut(&mut self, args: ClosureArguments) -> Self::Output {
66 #[allow(non_snake_case)]
67 let ($($var),*) = &mut self.data;
68 (self.func)(($($var),*), args)
73 impl_fn_mut_tuple!(A);
74 impl_fn_mut_tuple!(A B);
75 impl_fn_mut_tuple!(A B C);
76 impl_fn_mut_tuple!(A B C D);
77 impl_fn_mut_tuple!(A B C D E);