int -> i32

This commit is contained in:
Bastian Kauschke 2020-06-06 12:05:37 +02:00
parent c4840db8fc
commit a24c8977ee
12 changed files with 45 additions and 43 deletions

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@ -29,10 +29,10 @@ crate use self::util::elaborate_predicates;
pub use rustc_middle::traits::*;
/// An `Obligation` represents some trait reference (e.g., `int: Eq`) for
/// An `Obligation` represents some trait reference (e.g., `i32: Eq`) for
/// which the "impl_source" must be found. The process of finding a "impl_source" is
/// called "resolving" the `Obligation`. This process consists of
/// either identifying an `impl` (e.g., `impl Eq for int`) that
/// either identifying an `impl` (e.g., `impl Eq for i32`) that
/// satisfies the obligation, or else finding a bound that is in
/// scope. The eventual result is usually a `Selection` (defined below).
#[derive(Clone, PartialEq, Eq, Hash)]

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@ -63,11 +63,11 @@ impl PredicateSet<'tcx> {
fn insert(&mut self, pred: ty::Predicate<'tcx>) -> bool {
// We have to be careful here because we want
//
// for<'a> Foo<&'a int>
// for<'a> Foo<&'a i32>
//
// and
//
// for<'b> Foo<&'b int>
// for<'b> Foo<&'b i32>
//
// to be considered equivalent. So normalize all late-bound
// regions before we throw things into the underlying set.

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@ -393,23 +393,25 @@ pub type SelectionResult<'tcx, T> = Result<Option<T>, SelectionError<'tcx>>;
/// ```
/// impl<T:Clone> Clone<T> for Option<T> { ... } // Impl_1
/// impl<T:Clone> Clone<T> for Box<T> { ... } // Impl_2
/// impl Clone for int { ... } // Impl_3
/// impl Clone for i32 { ... } // Impl_3
///
/// fn foo<T:Clone>(concrete: Option<Box<int>>,
/// param: T,
/// mixed: Option<T>) {
/// fn foo<T: Clone>(concrete: Option<Box<i32>>, param: T, mixed: Option<T>) {
/// // Case A: Vtable points at a specific impl. Only possible when
/// // type is concretely known. If the impl itself has bounded
/// // type parameters, Vtable will carry resolutions for those as well:
/// concrete.clone(); // Vtable(Impl_1, [Vtable(Impl_2, [Vtable(Impl_3)])])
///
/// // Case A: ImplSource points at a specific impl. Only possible when
/// // type is concretely known. If the impl itself has bounded
/// // type parameters, ImplSource will carry resolutions for those as well:
/// concrete.clone(); // ImplSource(Impl_1, [ImplSource(Impl_2, [ImplSource(Impl_3)])])
/// // Case A: ImplSource points at a specific impl. Only possible when
/// // type is concretely known. If the impl itself has bounded
/// // type parameters, ImplSource will carry resolutions for those as well:
/// concrete.clone(); // ImplSource(Impl_1, [ImplSource(Impl_2, [ImplSource(Impl_3)])])
///
/// // Case B: ImplSource must be provided by caller. This applies when
/// // type is a type parameter.
/// param.clone(); // ImplSourceParam
/// // Case B: ImplSource must be provided by caller. This applies when
/// // type is a type parameter.
/// param.clone(); // ImplSourceParam
///
/// // Case C: A mix of cases A and B.
/// mixed.clone(); // ImplSource(Impl_1, [ImplSourceParam])
/// // Case C: A mix of cases A and B.
/// mixed.clone(); // ImplSource(Impl_1, [ImplSourceParam])
/// }
/// ```
///

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@ -599,12 +599,12 @@ impl<'a, 'tcx> SubstFolder<'a, 'tcx> {
///
/// ```
/// type Func<A> = fn(A);
/// type MetaFunc = for<'a> fn(Func<&'a int>)
/// type MetaFunc = for<'a> fn(Func<&'a i32>)
/// ```
///
/// The type `MetaFunc`, when fully expanded, will be
///
/// for<'a> fn(fn(&'a int))
/// for<'a> fn(fn(&'a i32))
/// ^~ ^~ ^~~
/// | | |
/// | | DebruijnIndex of 2
@ -613,7 +613,7 @@ impl<'a, 'tcx> SubstFolder<'a, 'tcx> {
/// Here the `'a` lifetime is bound in the outer function, but appears as an argument of the
/// inner one. Therefore, that appearance will have a DebruijnIndex of 2, because we must skip
/// over the inner binder (remember that we count De Bruijn indices from 1). However, in the
/// definition of `MetaFunc`, the binder is not visible, so the type `&'a int` will have a
/// definition of `MetaFunc`, the binder is not visible, so the type `&'a i32` will have a
/// De Bruijn index of 1. It's only during the substitution that we can see we must increase the
/// depth by 1 to account for the binder that we passed through.
///
@ -621,18 +621,18 @@ impl<'a, 'tcx> SubstFolder<'a, 'tcx> {
///
/// ```
/// type FuncTuple<A> = (A,fn(A));
/// type MetaFuncTuple = for<'a> fn(FuncTuple<&'a int>)
/// type MetaFuncTuple = for<'a> fn(FuncTuple<&'a i32>)
/// ```
///
/// Here the final type will be:
///
/// for<'a> fn((&'a int, fn(&'a int)))
/// for<'a> fn((&'a i32, fn(&'a i32)))
/// ^~~ ^~~
/// | |
/// DebruijnIndex of 1 |
/// DebruijnIndex of 2
///
/// As indicated in the diagram, here the same type `&'a int` is substituted once, but in the
/// As indicated in the diagram, here the same type `&'a i32` is substituted once, but in the
/// first case we do not increase the De Bruijn index and in the second case we do. The reason
/// is that only in the second case have we passed through a fn binder.
fn shift_vars_through_binders<T: TypeFoldable<'tcx>>(&self, val: T) -> T {

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@ -22,13 +22,13 @@ impl<'tcx> TypeWalker<'tcx> {
/// Skips the subtree corresponding to the last type
/// returned by `next()`.
///
/// Example: Imagine you are walking `Foo<Bar<int>, usize>`.
/// Example: Imagine you are walking `Foo<Bar<i32>, usize>`.
///
/// ```
/// let mut iter: TypeWalker = ...;
/// iter.next(); // yields Foo
/// iter.next(); // yields Bar<int>
/// iter.skip_current_subtree(); // skips int
/// iter.next(); // yields Bar<i32>
/// iter.skip_current_subtree(); // skips i32
/// iter.next(); // yields usize
/// ```
pub fn skip_current_subtree(&mut self) {

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@ -361,7 +361,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
// handle normalization within binders because
// otherwise we wind up a need to normalize when doing
// trait matching (since you can have a trait
// obligation like `for<'a> T::B : Fn(&'a int)`), but
// obligation like `for<'a> T::B: Fn(&'a i32)`), but
// we can't normalize with bound regions in scope. So
// far now we just ignore binders but only normalize
// if all bound regions are gone (and then we still

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@ -145,7 +145,7 @@ impl<'cx, 'tcx> TypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
// handle normalization within binders because
// otherwise we wind up a need to normalize when doing
// trait matching (since you can have a trait
// obligation like `for<'a> T::B : Fn(&'a int)`), but
// obligation like `for<'a> T::B: Fn(&'a i32)`), but
// we can't normalize with bound regions in scope. So
// far now we just ignore binders but only normalize
// if all bound regions are gone (and then we still

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@ -553,14 +553,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
///
/// Here is an example. Imagine we have a closure expression
/// and we desugared it so that the type of the expression is
/// `Closure`, and `Closure` expects an int as argument. Then it
/// `Closure`, and `Closure` expects `i32` as argument. Then it
/// is "as if" the compiler generated this impl:
///
/// impl Fn(int) for Closure { ... }
/// impl Fn(i32) for Closure { ... }
///
/// Now imagine our obligation is `Fn(usize) for Closure`. So far
/// Now imagine our obligation is `Closure: Fn(usize)`. So far
/// we have matched the self type `Closure`. At this point we'll
/// compare the `int` to `usize` and generate an error.
/// compare the `i32` to `usize` and generate an error.
///
/// Note that this checking occurs *after* the impl has selected,
/// because these output type parameters should not affect the

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@ -1762,7 +1762,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// The strategy is to:
//
// 1. Instantiate those regions to placeholder regions (e.g.,
// `for<'a> &'a int` becomes `&0 i32`.
// `for<'a> &'a i32` becomes `&0 i32`.
// 2. Produce something like `&'0 i32 : Copy`
// 3. Re-bind the regions back to `for<'a> &'a i32 : Copy`

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@ -1394,13 +1394,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
// That is, consider this case:
//
// ```
// trait SubTrait: SuperTrait<int> { }
// trait SubTrait: SuperTrait<i32> { }
// trait SuperTrait<A> { type T; }
//
// ... B: SubTrait<T = foo> ...
// ```
//
// We want to produce `<B as SuperTrait<int>>::T == foo`.
// We want to produce `<B as SuperTrait<i32>>::T == foo`.
// Find any late-bound regions declared in `ty` that are not
// declared in the trait-ref. These are not well-formed.

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@ -1468,7 +1468,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
///
/// ```
/// trait Foo { ... }
/// impl Foo for Vec<int> { ... }
/// impl Foo for Vec<i32> { ... }
/// impl Foo for Vec<usize> { ... }
/// ```
///

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@ -212,7 +212,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// errors in some cases, such as this one:
//
// ```
// fn foo<'x>(x: &'x int) {
// fn foo<'x>(x: &'x i32) {
// let a = 1;
// let mut z = x;
// z = &a;
@ -220,7 +220,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// ```
//
// The reason we might get an error is that `z` might be
// assigned a type like `&'x int`, and then we would have
// assigned a type like `&'x i32`, and then we would have
// a problem when we try to assign `&a` to `z`, because
// the lifetime of `&a` (i.e., the enclosing block) is
// shorter than `'x`.
@ -229,11 +229,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// expected type here is whatever type the user wrote, not
// the initializer's type. In this case the user wrote
// nothing, so we are going to create a type variable `Z`.
// Then we will assign the type of the initializer (`&'x
// int`) as a subtype of `Z`: `&'x int <: Z`. And hence we
// will instantiate `Z` as a type `&'0 int` where `'0` is
// a fresh region variable, with the constraint that `'x :
// '0`. So basically we're all set.
// Then we will assign the type of the initializer (`&'x i32`)
// as a subtype of `Z`: `&'x i32 <: Z`. And hence we
// will instantiate `Z` as a type `&'0 i32` where `'0` is
// a fresh region variable, with the constraint that `'x : '0`.
// So basically we're all set.
//
// Note that there are two tests to check that this remains true
// (`regions-reassign-{match,let}-bound-pointer.rs`).