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Dylan-DPCDylan-DPC
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Rollup merge of #95914 - c410-f3r:meta-vars, r=petrochenkov
Implement tuples using recursion Because it is c00l3r™, requires less repetition and can be used as a reference for external people. This change is non-essential and I am not sure about potential performance impacts so feel free to close this PR if desired. r? `@petrochenkov`
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‎library/core/src/tuple.rs

+74-67
Original file line numberDiff line numberDiff line change
@@ -3,68 +3,88 @@
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use crate::cmp::Ordering::*;
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use crate::cmp::*;
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// macro for implementing n-ary tuple functions and operations
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// Recursive macro for implementing n-ary tuple functions and operations
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//
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// Also provides implementations for tuples with lesser arity. For example, tuple_impls!(A B C)
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// will implement everything for (A, B, C), (A, B) and (A,).
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macro_rules! tuple_impls {
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( $( ( $( $T:ident )+ ) )+ ) => {
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$(
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<$($T:PartialEq),+> PartialEq for ($($T,)+) where last_type!($($T,)+): ?Sized {
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#[inline]
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fn eq(&self, other: &($($T,)+)) -> bool {
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$( ${ignore(T)} self.${index()} == other.${index()} )&&+
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}
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#[inline]
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fn ne(&self, other: &($($T,)+)) -> bool {
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$( ${ignore(T)} self.${index()} != other.${index()} )||+
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}
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// Stopping criteria (1-ary tuple)
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($T:ident) => {
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tuple_impls!(@impl $T);
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};
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// Running criteria (n-ary tuple, with n >= 2)
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($T:ident $( $U:ident )+) => {
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tuple_impls!($( $U )+);
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tuple_impls!(@impl $T $( $U )+);
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};
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// "Private" internal implementation
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(@impl $( $T:ident )+) => {
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<$($T:PartialEq),+> PartialEq for ($($T,)+)
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where
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last_type!($($T,)+): ?Sized
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{
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#[inline]
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fn eq(&self, other: &($($T,)+)) -> bool {
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$( ${ignore(T)} self.${index()} == other.${index()} )&&+
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}
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#[inline]
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fn ne(&self, other: &($($T,)+)) -> bool {
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$( ${ignore(T)} self.${index()} != other.${index()} )||+
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}
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}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<$($T:Eq),+> Eq for ($($T,)+) where last_type!($($T,)+): ?Sized {}
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#[stable(feature = "rust1", since = "1.0.0")]
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impl<$($T:Eq),+> Eq for ($($T,)+)
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where
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last_type!($($T,)+): ?Sized
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{}
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25-
#[stable(feature = "rust1", since = "1.0.0")]
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impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+)
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where
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last_type!($($T,)+): ?Sized
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{
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#[inline]
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fn partial_cmp(&self, other: &($($T,)+)) -> Option<Ordering> {
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lexical_partial_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[inline]
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fn lt(&self, other: &($($T,)+)) -> bool {
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lexical_ord!(lt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[inline]
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fn le(&self, other: &($($T,)+)) -> bool {
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lexical_ord!(le, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[inline]
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fn ge(&self, other: &($($T,)+)) -> bool {
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lexical_ord!(ge, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[inline]
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fn gt(&self, other: &($($T,)+)) -> bool {
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lexical_ord!(gt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[stable(feature = "rust1", since = "1.0.0")]
44+
impl<$($T:PartialOrd + PartialEq),+> PartialOrd for ($($T,)+)
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where
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last_type!($($T,)+): ?Sized
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{
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#[inline]
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fn partial_cmp(&self, other: &($($T,)+)) -> Option<Ordering> {
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lexical_partial_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[inline]
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fn lt(&self, other: &($($T,)+)) -> bool {
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lexical_ord!(lt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
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#[inline]
57+
fn le(&self, other: &($($T,)+)) -> bool {
58+
lexical_ord!(le, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
5059
}
60+
#[inline]
61+
fn ge(&self, other: &($($T,)+)) -> bool {
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lexical_ord!(ge, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
63+
}
64+
#[inline]
65+
fn gt(&self, other: &($($T,)+)) -> bool {
66+
lexical_ord!(gt, $( ${ignore(T)} self.${index()}, other.${index()} ),+)
67+
}
68+
}
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52-
#[stable(feature = "rust1", since = "1.0.0")]
53-
impl<$($T:Ord),+> Ord for ($($T,)+) where last_type!($($T,)+): ?Sized {
54-
#[inline]
55-
fn cmp(&self, other: &($($T,)+)) -> Ordering {
56-
lexical_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
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}
70+
#[stable(feature = "rust1", since = "1.0.0")]
71+
impl<$($T:Ord),+> Ord for ($($T,)+)
72+
where
73+
last_type!($($T,)+): ?Sized
74+
{
75+
#[inline]
76+
fn cmp(&self, other: &($($T,)+)) -> Ordering {
77+
lexical_cmp!($( ${ignore(T)} self.${index()}, other.${index()} ),+)
5878
}
79+
}
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60-
#[stable(feature = "rust1", since = "1.0.0")]
61-
impl<$($T:Default),+> Default for ($($T,)+) {
62-
#[inline]
63-
fn default() -> ($($T,)+) {
64-
($({ let x: $T = Default::default(); x},)+)
65-
}
81+
#[stable(feature = "rust1", since = "1.0.0")]
82+
impl<$($T:Default),+> Default for ($($T,)+) {
83+
#[inline]
84+
fn default() -> ($($T,)+) {
85+
($({ let x: $T = Default::default(); x},)+)
6686
}
67-
)+
87+
}
6888
}
6989
}
7090

@@ -105,17 +125,4 @@ macro_rules! last_type {
105125
($a:ident, $($rest_a:ident,)+) => { last_type!($($rest_a,)+) };
106126
}
107127

108-
tuple_impls! {
109-
(A)
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(A B)
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(A B C)
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(A B C D)
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(A B C D E)
114-
(A B C D E F)
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(A B C D E F G)
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(A B C D E F G H)
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(A B C D E F G H I)
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(A B C D E F G H I J)
119-
(A B C D E F G H I J K)
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(A B C D E F G H I J K L)
121-
}
128+
tuple_impls!(A B C D E F G H I J K L);

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