auto predicate = get_predicate_from_bound (
b->get_path (),
- tl::nullopt /*this will setup a PLACEHOLDER for self*/);
+ tl::nullopt /*this will setup a PLACEHOLDER for self*/,
+ BoundPolarity::RegularBound, false, true);
if (predicate.is_error ())
return &TraitReference::error_node ();
private:
void scan ();
+ bool
+ process_impl_block (HirId id, HIR::ImplBlock *impl,
+ std::vector<std::pair<HIR::TypePath *, HIR::ImplBlock *>>
+ &possible_trait_paths);
void assemble_marker_builtins ();
void add_trait_bound (HIR::Trait *trait);
void assemble_builtin_candidate (LangItem::Kind item);
HIR::TypePath &path,
tl::optional<std::reference_wrapper<HIR::Type>> associated_self,
BoundPolarity polarity = BoundPolarity::RegularBound,
- bool is_qualified_type = false);
+ bool is_qualified_type = false, bool is_super_trait = false);
bool check_for_unconstrained (
const std::vector<TyTy::SubstitutionParamMapping> ¶ms_to_constrain,
args.get_type_args ().push_back (std::unique_ptr<HIR::Type> (implicit_tuple));
// apply the arguments
- predicate.apply_generic_arguments (&args, false);
+ predicate.apply_generic_arguments (&args, false, false);
// finally inherit the trait bound
infered->inherit_bounds ({predicate});
return false;
}
+bool
+TypeBoundsProbe::process_impl_block (
+ HirId id, HIR::ImplBlock *impl,
+ std::vector<std::pair<HIR::TypePath *, HIR::ImplBlock *>>
+ &possible_trait_paths)
+{
+ // we are filtering for trait-impl-blocks
+ if (!impl->has_trait_ref ())
+ return true;
+
+ // can be recursive trait resolution
+ HIR::Trait *t = TraitResolver::ResolveHirItem (impl->get_trait_ref ());
+ if (t == nullptr)
+ return true;
+ // DefId trait_id = t->get_mappings ().get_defid ();
+ // if (context->trait_query_in_progress (trait_id))
+ // return true;
+
+ HirId impl_ty_id = impl->get_type ().get_mappings ().get_hirid ();
+ TyTy::BaseType *impl_type = nullptr;
+ if (!query_type (impl_ty_id, &impl_type))
+ return true;
+
+ if (!receiver->can_eq (impl_type, false))
+ {
+ if (!impl_type->can_eq (receiver, false))
+ return true;
+ }
+
+ possible_trait_paths.push_back ({&impl->get_trait_ref (), impl});
+ return true;
+}
+
void
TypeBoundsProbe::scan ()
{
possible_trait_paths;
mappings.iterate_impl_blocks (
[&] (HirId id, HIR::ImplBlock *impl) mutable -> bool {
- // we are filtering for trait-impl-blocks
- if (!impl->has_trait_ref ())
- return true;
-
- // can be recursive trait resolution
- HIR::Trait *t = TraitResolver::ResolveHirItem (impl->get_trait_ref ());
- if (t == nullptr)
- return true;
- DefId trait_id = t->get_mappings ().get_defid ();
- if (context->trait_query_in_progress (trait_id))
- return true;
-
- HirId impl_ty_id = impl->get_type ().get_mappings ().get_hirid ();
- TyTy::BaseType *impl_type = nullptr;
- if (!query_type (impl_ty_id, &impl_type))
- return true;
-
- if (!receiver->can_eq (impl_type, false))
- {
- if (!impl_type->can_eq (receiver, false))
- return true;
- }
-
- possible_trait_paths.push_back ({&impl->get_trait_ref (), impl});
- return true;
+ return process_impl_block (id, impl, possible_trait_paths);
});
for (auto &path : possible_trait_paths)
TypeCheckBase::get_predicate_from_bound (
HIR::TypePath &type_path,
tl::optional<std::reference_wrapper<HIR::Type>> associated_self,
- BoundPolarity polarity, bool is_qualified_type_path)
+ BoundPolarity polarity, bool is_qualified_type_path, bool is_super_trait)
{
TyTy::TypeBoundPredicate lookup = TyTy::TypeBoundPredicate::error ();
bool already_resolved
if (!args.is_empty () || predicate.requires_generic_args ())
{
// this is applying generic arguments to a trait reference
- predicate.apply_generic_arguments (&args, associated_self.has_value ());
+ predicate.apply_generic_arguments (&args, associated_self.has_value (),
+ is_super_trait);
}
context->insert_resolved_predicate (type_path.get_mappings ().get_hirid (),
void
TypeBoundPredicate::apply_generic_arguments (HIR::GenericArgs *generic_args,
- bool has_associated_self)
+ bool has_associated_self,
+ bool is_super_trait)
{
rust_assert (!substitutions.empty ());
if (has_associated_self)
Resolver::TypeCheckContext::get ()->regions_from_generic_args (
*generic_args));
- apply_argument_mappings (args);
+ apply_argument_mappings (args, is_super_trait);
}
void
TypeBoundPredicate::apply_argument_mappings (
- SubstitutionArgumentMappings &arguments)
+ SubstitutionArgumentMappings &arguments, bool is_super_trait)
{
used_arguments = arguments;
error_flag |= used_arguments.is_error ();
auto &subst_mappings = used_arguments;
+
+ bool substs_need_bounds_check = !is_super_trait;
for (auto &sub : get_substs ())
{
SubstitutionArg arg = SubstitutionArg::error ();
bool ok
= subst_mappings.get_argument_for_symbol (sub.get_param_ty (), &arg);
if (ok && arg.get_tyty () != nullptr)
- sub.fill_param_ty (subst_mappings, subst_mappings.get_locus ());
+ sub.fill_param_ty (subst_mappings, subst_mappings.get_locus (),
+ substs_need_bounds_check);
}
// associated argument mappings
auto adjusted
= super_trait.adjust_mappings_for_this (used_arguments,
true /*trait mode*/);
- super_trait.apply_argument_mappings (adjusted);
+ super_trait.apply_argument_mappings (adjusted, is_super_trait);
}
}
bool
SubstitutionParamMapping::fill_param_ty (
- SubstitutionArgumentMappings &subst_mappings, location_t locus)
+ SubstitutionArgumentMappings &subst_mappings, location_t locus,
+ bool needs_bounds_check)
{
SubstitutionArg arg = SubstitutionArg::error ();
bool ok = subst_mappings.get_argument_for_symbol (get_param_ty (), &arg);
rust_debug_loc (locus,
"fill_param_ty bounds_compatible: param %s type %s",
param->get_name ().c_str (), type.get_name ().c_str ());
-
- if (!param->is_implicit_self_trait ())
+ if (needs_bounds_check && !param->is_implicit_self_trait ())
{
if (!param->bounds_compatible (type, locus, true))
return false;
std::string as_string () const;
bool fill_param_ty (SubstitutionArgumentMappings &subst_mappings,
- location_t locus);
+ location_t locus, bool needs_bounds_check = true);
SubstitutionParamMapping clone () const;
std::string get_name () const;
- // check that this predicate is object-safe see:
+ // check that this is object-safe see:
// https://doc.rust-lang.org/reference/items/traits.html#object-safety
bool is_object_safe (bool emit_error, location_t locus) const;
void apply_generic_arguments (HIR::GenericArgs *generic_args,
- bool has_associated_self);
+ bool has_associated_self, bool is_super_trait);
- void apply_argument_mappings (SubstitutionArgumentMappings &arguments);
+ void apply_argument_mappings (SubstitutionArgumentMappings &arguments,
+ bool is_super_trait);
bool contains_item (const std::string &search) const;
-// { dg-additional-options "-frust-compile-until=typecheck" }
+// { dg-additional-options "-w" }
#![feature(intrinsics)]
--- /dev/null
+// { dg-options "-w" }
+mod core {
+ mod option {
+ pub enum Option<T> {
+ #[lang = "None"]
+ None,
+ #[lang = "Some"]
+ Some(T),
+ }
+ }
+
+ mod marker {
+ #[lang = "sized"]
+ pub trait Sized {}
+ }
+
+ mod cmp {
+ use super::marker::Sized;
+ use super::option::Option;
+
+ pub enum Ordering {
+ Less = -1,
+ Equal = 0,
+ Greater = 1,
+ }
+
+ #[lang = "eq"]
+ pub trait PartialEq<Rhs: ?Sized = Self> {
+ fn eq(&self, other: &Rhs) -> bool;
+
+ fn ne(&self, other: &Rhs) -> bool {
+ !self.eq(other)
+ }
+ }
+
+ #[lang = "partial_ord"]
+ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
+ fn partial_cmp(&self, other: &Rhs) -> Option<Ordering>;
+ }
+ }
+}
+
+use core::cmp::{Ordering, PartialEq, PartialOrd};
+use core::marker::Sized;
+use core::option::Option;
+
+impl PartialEq for i32 {
+ fn eq(&self, other: &Self) -> bool {
+ false
+ }
+}
+
+impl PartialOrd for i32 {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ Option::Some(Ordering::Equal)
+ }
+}
+
+struct Foo {
+ a: i32,
+}
+
+impl PartialEq for Foo {
+ fn eq(&self, other: &'_ Self) -> bool {
+ ::core::cmp::PartialEq::eq(&self.a, &other.a)
+ }
+}
Option::Some(Ordering::Equal)
}
}
+
+ fn lt(&self, other: &Self) -> bool {
+ *self < *other
+ }
+ fn le(&self, other: &Self) -> bool {
+ *self <= *other
+ }
+ fn ge(&self, other: &Self) -> bool {
+ *self >= *other
+ }
+ fn gt(&self, other: &Self) -> bool {
+ *self > *other
+ }
}
impl Eq for i32 {}
Option::Some(Ordering::Equal)
}
}
+
+ fn lt(&self, other: &Self) -> bool {
+ *self < *other
+ }
+ fn le(&self, other: &Self) -> bool {
+ *self <= *other
+ }
+ fn ge(&self, other: &Self) -> bool {
+ *self >= *other
+ }
+ fn gt(&self, other: &Self) -> bool {
+ *self > *other
+ }
}
impl Eq for i32 {}
--- /dev/null
+// { dg-options "-w" }
+// { dg-output "less\r*\n" }
+
+#![feature(intrinsics)]
+
+mod core {
+ mod option {
+ // #[rustc_diagnostic_item = "option_type"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub enum Option<T> {
+ /// No value
+ #[lang = "None"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ None,
+ /// Some value `T`
+ #[lang = "Some"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+ }
+ }
+
+ mod marker {
+ #[lang = "phantom_data"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub struct PhantomData<T: ?Sized>;
+
+ #[unstable(feature = "structural_match", issue = "31434")]
+ // #[rustc_on_unimplemented(message = "the type `{Self}` does not `#[derive(PartialEq)]`")]
+ #[lang = "structural_peq"]
+ pub trait StructuralPartialEq {
+ // Empty.
+ }
+
+ #[unstable(feature = "structural_match", issue = "31434")]
+ // #[rustc_on_unimplemented(message = "the type `{Self}` does not `#[derive(Eq)]`")]
+ #[lang = "structural_teq"]
+ pub trait StructuralEq {
+ // Empty.
+ }
+
+ #[stable(feature = "rust1", since = "1.0.0")]
+ #[lang = "sized"]
+ // #[rustc_on_unimplemented(
+ // message = "the size for values of type `{Self}` cannot be known at compilation time",
+ // label = "doesn't have a size known at compile-time"
+ // )]
+ // #[fundamental] // for Default, for example, which requires that `[T]: !Default` be evaluatable
+ // #[rustc_specialization_trait]
+ pub trait Sized {
+ // Empty.
+ }
+ }
+
+ mod cmp {
+ use super::marker::Sized;
+ use super::option::Option;
+
+ // #[derive(Clone, Copy, PartialEq, Debug, Hash)]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub enum Ordering {
+ /// An ordering where a compared value is less than another.
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Less = -1,
+ /// An ordering where a compared value is equal to another.
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Equal = 0,
+ /// An ordering where a compared value is greater than another.
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Greater = 1,
+ }
+
+ #[lang = "eq"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ #[doc(alias = "==")]
+ #[doc(alias = "!=")]
+ // #[rustc_on_unimplemented(
+ // message = "can't compare `{Self}` with `{Rhs}`",
+ // label = "no implementation for `{Self} == {Rhs}`"
+ // )]
+ pub trait PartialEq<Rhs: ?Sized = Self> {
+ /// This method tests for `self` and `other` values to be equal, and is used
+ /// by `==`.
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn eq(&self, other: &Rhs) -> bool;
+
+ fn ne(&self, other: &Rhs) -> bool {
+ !self.eq(other)
+ }
+ }
+
+ #[doc(alias = "==")]
+ #[doc(alias = "!=")]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub trait Eq: PartialEq<Self> {
+ // this method is used solely by #[deriving] to assert
+ // that every component of a type implements #[deriving]
+ // itself, the current deriving infrastructure means doing this
+ // assertion without using a method on this trait is nearly
+ // impossible.
+ //
+ // This should never be implemented by hand.
+ #[doc(hidden)]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn assert_receiver_is_total_eq(&self) {}
+ }
+
+ #[lang = "partial_ord"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ #[doc(alias = ">")]
+ #[doc(alias = "<")]
+ #[doc(alias = "<=")]
+ #[doc(alias = ">=")]
+ // #[rustc_on_unimplemented(
+ // message = "can't compare `{Self}` with `{Rhs}`",
+ // label = "no implementation for `{Self} < {Rhs}` and `{Self} > {Rhs}`"
+ // )]
+ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
+ /// This method returns an ordering between `self` and `other` values if one exists.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::cmp::Ordering;
+ ///
+ /// let result = 1.0.partial_cmp(&2.0);
+ /// assert_eq!(result, Some(Ordering::Less));
+ ///
+ /// let result = 1.0.partial_cmp(&1.0);
+ /// assert_eq!(result, Some(Ordering::Equal));
+ ///
+ /// let result = 2.0.partial_cmp(&1.0);
+ /// assert_eq!(result, Some(Ordering::Greater));
+ /// ```
+ ///
+ /// When comparison is impossible:
+ ///
+ /// ```
+ /// let result = f64::NAN.partial_cmp(&1.0);
+ /// assert_eq!(result, None);
+ /// ```
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn partial_cmp(&self, other: &Rhs) -> Option<Ordering>;
+
+ /// This method tests less than (for `self` and `other`) and is used by the `<` operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 1.0 < 2.0;
+ /// assert_eq!(result, true);
+ ///
+ /// let result = 2.0 < 1.0;
+ /// assert_eq!(result, false);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn lt(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Less) => true,
+ _ => false,
+ }
+ }
+
+ /// This method tests less than or equal to (for `self` and `other`) and is used by the `<=`
+ /// operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 1.0 <= 2.0;
+ /// assert_eq!(result, true);
+ ///
+ /// let result = 2.0 <= 2.0;
+ /// assert_eq!(result, true);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn le(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Less | Ordering::Equal) => true,
+ _ => false,
+ }
+ }
+
+ /// This method tests greater than (for `self` and `other`) and is used by the `>` operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 1.0 > 2.0;
+ /// assert_eq!(result, false);
+ ///
+ /// let result = 2.0 > 2.0;
+ /// assert_eq!(result, false);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn gt(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Greater) => true,
+ _ => false,
+ }
+ }
+
+ /// This method tests greater than or equal to (for `self` and `other`) and is used by the `>=`
+ /// operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 2.0 >= 1.0;
+ /// assert_eq!(result, true);
+ ///
+ /// let result = 2.0 >= 2.0;
+ /// assert_eq!(result, true);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn ge(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Greater | Ordering::Equal) => true,
+ _ => false,
+ }
+ }
+ }
+
+ #[doc(alias = "<")]
+ #[doc(alias = ">")]
+ #[doc(alias = "<=")]
+ #[doc(alias = ">=")]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub trait Ord: Eq + PartialOrd<Self> {
+ /// This method returns an [`Ordering`] between `self` and `other`.
+ ///
+ /// By convention, `self.cmp(&other)` returns the ordering matching the expression
+ /// `self <operator> other` if true.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::cmp::Ordering;
+ ///
+ /// assert_eq!(5.cmp(&10), Ordering::Less);
+ /// assert_eq!(10.cmp(&5), Ordering::Greater);
+ /// assert_eq!(5.cmp(&5), Ordering::Equal);
+ /// ```
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn cmp(&self, other: &Self) -> Ordering;
+
+ /// Compares and returns the maximum of two values.
+ ///
+ /// Returns the second argument if the comparison determines them to be equal.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// assert_eq!(2, 1.max(2));
+ /// assert_eq!(2, 2.max(2));
+ /// ```
+ #[stable(feature = "ord_max_min", since = "1.21.0")]
+ #[must_use]
+ fn max(self, other: Self) -> Self
+ where
+ Self: Sized,
+ {
+ self
+ }
+
+ /// Compares and returns the minimum of two values.
+ ///
+ /// Returns the first argument if the comparison determines them to be equal.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// assert_eq!(1, 1.min(2));
+ /// assert_eq!(2, 2.min(2));
+ /// ```
+ #[stable(feature = "ord_max_min", since = "1.21.0")]
+ #[must_use]
+ fn min(self, other: Self) -> Self
+ where
+ Self: Sized,
+ {
+ self
+ }
+
+ /// Restrict a value to a certain interval.
+ ///
+ /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
+ /// less than `min`. Otherwise this returns `self`.
+ ///
+ /// # Panics
+ ///
+ /// Panics if `min > max`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// #![feature(clamp)]
+ ///
+ /// assert!((-3).clamp(-2, 1) == -2);
+ /// assert!(0.clamp(-2, 1) == 0);
+ /// assert!(2.clamp(-2, 1) == 1);
+ /// ```
+ #[must_use]
+ #[unstable(feature = "clamp", issue = "44095")]
+ fn clamp(self, min: Self, max: Self) -> Self
+ where
+ Self: Sized,
+ {
+ if self < min {
+ min
+ } else if self > max {
+ max
+ } else {
+ self
+ }
+ }
+ }
+ }
+
+ pub mod intrinsics {
+ #[lang = "discriminant_kind"]
+ pub trait DiscriminantKind {
+ #[lang = "discriminant_type"]
+ type Discriminant;
+ }
+
+ extern "rust-intrinsic" {
+ pub fn discriminant_value<T>(v: &T) -> <T as DiscriminantKind>::Discriminant;
+ }
+ }
+}
+
+use core::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
+use core::marker::Sized;
+use core::option::Option;
+
+// for comparing discriminant_value
+impl PartialEq for isize {
+ fn eq(&self, other: &Self) -> bool {
+ *self == *other
+ }
+}
+
+// for comparing discriminant_value
+impl PartialOrd for isize {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ if *self > *other {
+ Option::Some(Ordering::Greater)
+ } else if *self < *other {
+ Option::Some(Ordering::Less)
+ } else {
+ Option::Some(Ordering::Equal)
+ }
+ }
+
+ fn lt(&self, other: &Self) -> bool {
+ *self < *other
+ }
+ fn le(&self, other: &Self) -> bool {
+ *self <= *other
+ }
+ fn ge(&self, other: &Self) -> bool {
+ *self >= *other
+ }
+ fn gt(&self, other: &Self) -> bool {
+ *self > *other
+ }
+}
+
+impl PartialEq for i32 {
+ fn eq(&self, other: &Self) -> bool {
+ *self == *other
+ }
+}
+impl Eq for i32 {}
+
+impl PartialOrd for i32 {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ if *self > *other {
+ Option::Some(Ordering::Greater)
+ } else if *self < *other {
+ Option::Some(Ordering::Less)
+ } else {
+ Option::Some(Ordering::Equal)
+ }
+ }
+
+ fn lt(&self, other: &Self) -> bool {
+ *self < *other
+ }
+ fn le(&self, other: &Self) -> bool {
+ *self <= *other
+ }
+ fn ge(&self, other: &Self) -> bool {
+ *self >= *other
+ }
+ fn gt(&self, other: &Self) -> bool {
+ *self > *other
+ }
+}
+
+impl Ord for i32 {
+ fn cmp(&self, other: &Self) -> Ordering {
+ if *self > *other {
+ Ordering::Greater
+ } else if *self < *other {
+ Ordering::Less
+ } else {
+ Ordering::Equal
+ }
+ }
+}
+
+// ------------
+
+#[derive(Ord, PartialOrd, PartialEq, Eq)]
+struct Bar {
+ a: i32,
+ b: i32,
+}
+
+extern "C" {
+ fn puts(s: *const i8);
+}
+
+fn print(s: &str) {
+ unsafe {
+ puts(s as *const str as *const i8);
+ }
+}
+
+fn main() -> i32 {
+ let x = Bar { a: 1, b: 2 };
+ let y = Bar { a: 1, b: 3 };
+
+ match x.partial_cmp(&y) {
+ Option::Some(Ordering::Less) => print("less"),
+ Option::Some(Ordering::Greater) => print("greater"),
+ Option::Some(Ordering::Equal) => print("equal"),
+ _ => print("none"),
+ }
+
+ 0
+}
--- /dev/null
+// { dg-additional-options "-w" }
+/* { dg-output "Foo A < B\r?\nFoo B < C\r?\nFoo C == C\r?\nBar x < y\r?\nBarFull s1 < s2\r?\n" } */
+
+#![feature(intrinsics)]
+
+mod core {
+ mod option {
+ // #[rustc_diagnostic_item = "option_type"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub enum Option<T> {
+ /// No value
+ #[lang = "None"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ None,
+ /// Some value `T`
+ #[lang = "Some"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+ }
+ }
+
+ mod marker {
+ #[lang = "phantom_data"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub struct PhantomData<T: ?Sized>;
+
+ #[unstable(feature = "structural_match", issue = "31434")]
+ // #[rustc_on_unimplemented(message = "the type `{Self}` does not `#[derive(PartialEq)]`")]
+ #[lang = "structural_peq"]
+ pub trait StructuralPartialEq {
+ // Empty.
+ }
+
+ #[unstable(feature = "structural_match", issue = "31434")]
+ // #[rustc_on_unimplemented(message = "the type `{Self}` does not `#[derive(Eq)]`")]
+ #[lang = "structural_teq"]
+ pub trait StructuralEq {
+ // Empty.
+ }
+
+ #[stable(feature = "rust1", since = "1.0.0")]
+ #[lang = "sized"]
+ // #[rustc_on_unimplemented(
+ // message = "the size for values of type `{Self}` cannot be known at compilation time",
+ // label = "doesn't have a size known at compile-time"
+ // )]
+ // #[fundamental] // for Default, for example, which requires that `[T]: !Default` be evaluatable
+ // #[rustc_specialization_trait]
+ pub trait Sized {
+ // Empty.
+ }
+ }
+
+ mod cmp {
+ use super::marker::Sized;
+ use super::option::Option;
+
+ // #[derive(Clone, Copy, PartialEq, Debug, Hash)]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub enum Ordering {
+ /// An ordering where a compared value is less than another.
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Less = -1,
+ /// An ordering where a compared value is equal to another.
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Equal = 0,
+ /// An ordering where a compared value is greater than another.
+ #[stable(feature = "rust1", since = "1.0.0")]
+ Greater = 1,
+ }
+
+ #[lang = "eq"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ #[doc(alias = "==")]
+ #[doc(alias = "!=")]
+ // #[rustc_on_unimplemented(
+ // message = "can't compare `{Self}` with `{Rhs}`",
+ // label = "no implementation for `{Self} == {Rhs}`"
+ // )]
+ pub trait PartialEq<Rhs: ?Sized = Self> {
+ /// This method tests for `self` and `other` values to be equal, and is used
+ /// by `==`.
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn eq(&self, other: &Rhs) -> bool;
+
+ fn ne(&self, other: &Rhs) -> bool {
+ !self.eq(other)
+ }
+ }
+
+ #[doc(alias = "==")]
+ #[doc(alias = "!=")]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub trait Eq: PartialEq<Self> {
+ // this method is used solely by #[deriving] to assert
+ // that every component of a type implements #[deriving]
+ // itself, the current deriving infrastructure means doing this
+ // assertion without using a method on this trait is nearly
+ // impossible.
+ //
+ // This should never be implemented by hand.
+ #[doc(hidden)]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn assert_receiver_is_total_eq(&self) {}
+ }
+
+ #[lang = "partial_ord"]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ #[doc(alias = ">")]
+ #[doc(alias = "<")]
+ #[doc(alias = "<=")]
+ #[doc(alias = ">=")]
+ // #[rustc_on_unimplemented(
+ // message = "can't compare `{Self}` with `{Rhs}`",
+ // label = "no implementation for `{Self} < {Rhs}` and `{Self} > {Rhs}`"
+ // )]
+ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
+ /// This method returns an ordering between `self` and `other` values if one exists.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::cmp::Ordering;
+ ///
+ /// let result = 1.0.partial_cmp(&2.0);
+ /// assert_eq!(result, Some(Ordering::Less));
+ ///
+ /// let result = 1.0.partial_cmp(&1.0);
+ /// assert_eq!(result, Some(Ordering::Equal));
+ ///
+ /// let result = 2.0.partial_cmp(&1.0);
+ /// assert_eq!(result, Some(Ordering::Greater));
+ /// ```
+ ///
+ /// When comparison is impossible:
+ ///
+ /// ```
+ /// let result = f64::NAN.partial_cmp(&1.0);
+ /// assert_eq!(result, None);
+ /// ```
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn partial_cmp(&self, other: &Rhs) -> Option<Ordering>;
+
+ /// This method tests less than (for `self` and `other`) and is used by the `<` operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 1.0 < 2.0;
+ /// assert_eq!(result, true);
+ ///
+ /// let result = 2.0 < 1.0;
+ /// assert_eq!(result, false);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn lt(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Less) => true,
+ _ => false,
+ }
+ }
+
+ /// This method tests less than or equal to (for `self` and `other`) and is used by the `<=`
+ /// operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 1.0 <= 2.0;
+ /// assert_eq!(result, true);
+ ///
+ /// let result = 2.0 <= 2.0;
+ /// assert_eq!(result, true);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn le(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Less | Ordering::Equal) => true,
+ _ => false,
+ }
+ }
+
+ /// This method tests greater than (for `self` and `other`) and is used by the `>` operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 1.0 > 2.0;
+ /// assert_eq!(result, false);
+ ///
+ /// let result = 2.0 > 2.0;
+ /// assert_eq!(result, false);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn gt(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Greater) => true,
+ _ => false,
+ }
+ }
+
+ /// This method tests greater than or equal to (for `self` and `other`) and is used by the `>=`
+ /// operator.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// let result = 2.0 >= 1.0;
+ /// assert_eq!(result, true);
+ ///
+ /// let result = 2.0 >= 2.0;
+ /// assert_eq!(result, true);
+ /// ```
+ #[inline]
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn ge(&self, other: &Rhs) -> bool {
+ match self.partial_cmp(other) {
+ Option::Some(Ordering::Greater | Ordering::Equal) => true,
+ _ => false,
+ }
+ }
+ }
+
+ #[doc(alias = "<")]
+ #[doc(alias = ">")]
+ #[doc(alias = "<=")]
+ #[doc(alias = ">=")]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ pub trait Ord: Eq + PartialOrd<Self> {
+ /// This method returns an [`Ordering`] between `self` and `other`.
+ ///
+ /// By convention, `self.cmp(&other)` returns the ordering matching the expression
+ /// `self <operator> other` if true.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::cmp::Ordering;
+ ///
+ /// assert_eq!(5.cmp(&10), Ordering::Less);
+ /// assert_eq!(10.cmp(&5), Ordering::Greater);
+ /// assert_eq!(5.cmp(&5), Ordering::Equal);
+ /// ```
+ #[must_use]
+ #[stable(feature = "rust1", since = "1.0.0")]
+ fn cmp(&self, other: &Self) -> Ordering;
+
+ /// Compares and returns the maximum of two values.
+ ///
+ /// Returns the second argument if the comparison determines them to be equal.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// assert_eq!(2, 1.max(2));
+ /// assert_eq!(2, 2.max(2));
+ /// ```
+ #[stable(feature = "ord_max_min", since = "1.21.0")]
+ #[must_use]
+ fn max(self, other: Self) -> Self
+ where
+ Self: Sized,
+ {
+ self
+ }
+
+ /// Compares and returns the minimum of two values.
+ ///
+ /// Returns the first argument if the comparison determines them to be equal.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// assert_eq!(1, 1.min(2));
+ /// assert_eq!(2, 2.min(2));
+ /// ```
+ #[stable(feature = "ord_max_min", since = "1.21.0")]
+ #[must_use]
+ fn min(self, other: Self) -> Self
+ where
+ Self: Sized,
+ {
+ self
+ }
+
+ /// Restrict a value to a certain interval.
+ ///
+ /// Returns `max` if `self` is greater than `max`, and `min` if `self` is
+ /// less than `min`. Otherwise this returns `self`.
+ ///
+ /// # Panics
+ ///
+ /// Panics if `min > max`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// #![feature(clamp)]
+ ///
+ /// assert!((-3).clamp(-2, 1) == -2);
+ /// assert!(0.clamp(-2, 1) == 0);
+ /// assert!(2.clamp(-2, 1) == 1);
+ /// ```
+ #[must_use]
+ #[unstable(feature = "clamp", issue = "44095")]
+ fn clamp(self, min: Self, max: Self) -> Self
+ where
+ Self: Sized,
+ {
+ if self < min {
+ min
+ } else if self > max {
+ max
+ } else {
+ self
+ }
+ }
+ }
+ }
+
+ pub mod intrinsics {
+ #[lang = "discriminant_kind"]
+ pub trait DiscriminantKind {
+ #[lang = "discriminant_type"]
+ type Discriminant;
+ }
+
+ extern "rust-intrinsic" {
+ pub fn discriminant_value<T>(v: &T) -> <T as DiscriminantKind>::Discriminant;
+ }
+ }
+}
+
+use core::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
+use core::marker::Sized;
+use core::option::Option;
+
+// for comparing discriminant_value
+impl PartialEq for isize {
+ fn eq(&self, other: &Self) -> bool {
+ *self == *other
+ }
+}
+
+// for comparing discriminant_value
+impl PartialOrd for isize {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ if *self > *other {
+ Option::Some(Ordering::Greater)
+ } else if *self < *other {
+ Option::Some(Ordering::Less)
+ } else {
+ Option::Some(Ordering::Equal)
+ }
+ }
+
+ fn lt(&self, other: &Self) -> bool {
+ *self < *other
+ }
+ fn le(&self, other: &Self) -> bool {
+ *self <= *other
+ }
+ fn ge(&self, other: &Self) -> bool {
+ *self >= *other
+ }
+ fn gt(&self, other: &Self) -> bool {
+ *self > *other
+ }
+}
+
+impl PartialEq for i32 {
+ fn eq(&self, other: &Self) -> bool {
+ *self == *other
+ }
+}
+
+impl PartialOrd for i32 {
+ fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+ if *self > *other {
+ Option::Some(Ordering::Greater)
+ } else if *self < *other {
+ Option::Some(Ordering::Less)
+ } else {
+ Option::Some(Ordering::Equal)
+ }
+ }
+
+ fn lt(&self, other: &Self) -> bool {
+ *self < *other
+ }
+ fn le(&self, other: &Self) -> bool {
+ *self <= *other
+ }
+ fn ge(&self, other: &Self) -> bool {
+ *self >= *other
+ }
+ fn gt(&self, other: &Self) -> bool {
+ *self > *other
+ }
+}
+
+impl Ord for i32 {
+ fn cmp(&self, other: &Self) -> Ordering {
+ if *self > *other {
+ Ordering::Greater
+ } else if *self < *other {
+ Ordering::Less
+ } else {
+ Ordering::Equal
+ }
+ }
+}
+
+impl Eq for i32 {}
+
+#[derive(PartialEq, PartialOrd)]
+enum Foo {
+ A,
+ B(i32, i32, i32),
+ C { inner: i32, outer: i32 },
+}
+
+#[derive(Ord, PartialOrd, PartialEq, Eq)]
+struct Bar {
+ a: i32,
+}
+
+#[derive(Ord, PartialOrd, PartialEq, Eq)]
+struct BarFull {
+ a: i32,
+ b: i32,
+ c: i32,
+ d: i32,
+}
+
+extern "C" {
+ fn puts(s: *const i8);
+}
+
+fn print(s: &str) {
+ unsafe {
+ puts(s as *const str as *const i8);
+ }
+}
+
+fn main() -> i32 {
+ // Enum comparison
+ let a = Foo::A;
+ let b = Foo::B(15, 14, 13);
+ let c = Foo::C {
+ inner: 10,
+ outer: 20,
+ };
+
+ match a.partial_cmp(&b) {
+ Option::Some(Ordering::Less) => print("Foo A < B"),
+ Option::Some(Ordering::Greater) => print("Foo A > B"),
+ Option::Some(Ordering::Equal) => print("Foo A == B"),
+ _ => print("Foo A ? B"),
+ }
+
+ match b.partial_cmp(&c) {
+ Option::Some(Ordering::Less) => print("Foo B < C"),
+ Option::Some(Ordering::Greater) => print("Foo B > C"),
+ Option::Some(Ordering::Equal) => print("Foo B == C"),
+ _ => print("Foo B ? C"),
+ }
+
+ match c.partial_cmp(&c) {
+ Option::Some(Ordering::Less) => print("Foo C < C ???"),
+ Option::Some(Ordering::Greater) => print("Foo C > C ???"),
+ Option::Some(Ordering::Equal) => print("Foo C == C"),
+ _ => print("Foo C ? C"),
+ }
+
+ // Struct comparison: Bar
+ let x = Bar { a: 10 };
+ let y = Bar { a: 20 };
+
+ if x < y {
+ print("Bar x < y");
+ } else if x > y {
+ print("Bar x > y");
+ } else {
+ print("Bar x == y");
+ }
+
+ // Struct comparison: BarFull
+ let s1 = BarFull {
+ a: 1,
+ b: 2,
+ c: 3,
+ d: 4,
+ };
+ let s2 = BarFull {
+ a: 1,
+ b: 2,
+ c: 3,
+ d: 5,
+ };
+
+ match s1.cmp(&s2) {
+ Ordering::Less => print("BarFull s1 < s2"),
+ Ordering::Greater => print("BarFull s1 > s2"),
+ Ordering::Equal => print("BarFull s1 == s2"),
+ }
+
+ 0
+}