53 lines
1.2 KiB
Rust
53 lines
1.2 KiB
Rust
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// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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use alloc::boxed::Box;
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use core::kinds::Send;
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use core::ops::FnOnce;
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pub struct Thunk<A=(),R=()> {
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invoke: Box<Invoke<A,R>+Send>
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}
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impl<R> Thunk<(),R> {
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pub fn new<F>(func: F) -> Thunk<(),R>
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where F : FnOnce() -> R, F : Send
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{
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Thunk::with_arg(move|: ()| func())
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}
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}
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impl<A,R> Thunk<A,R> {
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pub fn with_arg<F>(func: F) -> Thunk<A,R>
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where F : FnOnce(A) -> R, F : Send
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{
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Thunk {
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invoke: box func
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}
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}
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pub fn invoke(self, arg: A) -> R {
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self.invoke.invoke(arg)
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}
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}
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pub trait Invoke<A=(),R=()> {
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fn invoke(self: Box<Self>, arg: A) -> R;
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}
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impl<A,R,F> Invoke<A,R> for F
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where F : FnOnce(A) -> R
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{
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fn invoke(self: Box<F>, arg: A) -> R {
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let f = *self;
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f(arg)
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}
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}
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