1 // Copyright 2015-2016 Brian Smith. 2 // 3 // Permission to use, copy, modify, and/or distribute this software for any 4 // purpose with or without fee is hereby granted, provided that the above 5 // copyright notice and this permission notice appear in all copies. 6 // 7 // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES 8 // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9 // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 10 // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11 // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 14 15 // TODO: Replace this with use of the array_map feature 16 // (https://github.com/rust-lang/rust/issues/75243) when it becomes stable. 17 18 pub(crate) trait Map<A, B, BArray> { array_map(self, f: impl Fn(A) -> B) -> BArray19 fn array_map(self, f: impl Fn(A) -> B) -> BArray; 20 } 21 22 macro_rules! impl_map { 23 ( $n:expr, [ $( $elem:ident ),+ ] ) => { 24 impl<A, B> Map<A, B, [B; $n]> for [A; $n] { 25 #[inline] 26 fn array_map(self, f: impl Fn(A) -> B) -> [B; $n] { 27 let [ $( $elem ),+ ] = self; 28 [ $( f($elem) ),+ ] 29 } 30 } 31 } 32 } 33 34 impl_map!(4, [a, b, c, d]); 35 impl_map!(8, [a, b, c, d, e, f, g, h]); 36