rust-analyzer

diff --git a/crates/hir-def/src/item_tree/lower.rs b/crates/hir-def/src/item_tree/lower.rs
index 27705cbbbd..d4d3c5ef19 100644
--- a/crates/hir-def/src/item_tree/lower.rs
+++ b/crates/hir-def/src/item_tree/lower.rs

@@ -659,15 +659,16 @@ fn desugar_future_path(orig: TypeRef) -> Path {

let path = path![core::future::Future];

let mut generic_args: Vec<_> =

std::iter::repeat(None).take(path.segments().len() - 1).collect();

- let mut last = GenericArgs::empty();

let binding = AssociatedTypeBinding {

args: None,

type_ref: Some(orig),

- bounds: Vec::new(),

+ bounds: Box::default(),

};

- last.bindings.push(binding);

- generic_args.push(Some(Interned::new(last)));

+ generic_args.push(Some(Interned::new(GenericArgs {

+ bindings: Box::new([binding]),

+ ..GenericArgs::empty()

+ })));

Path::from_known_path(path, generic_args)

}

diff --git a/crates/hir-def/src/path.rs b/crates/hir-def/src/path.rs
index f53bd4f618..36d4c36a26 100644
--- a/crates/hir-def/src/path.rs
+++ b/crates/hir-def/src/path.rs

@@ -49,7 +49,7 @@ pub struct Path {

/// also includes bindings of associated types, like in `Iterator<Item = Foo>`.

#[derive(Debug, Clone, PartialEq, Eq, Hash)]

pub struct GenericArgs {

- pub args: Vec<GenericArg>,

+ pub args: Box<[GenericArg]>,

/// This specifies whether the args contain a Self type as the first

/// element. This is the case for path segments like `<T as Trait>`, where

/// `T` is actually a type parameter for the path `Trait` specifying the

@@ -57,7 +57,7 @@ pub struct GenericArgs {

/// is left out.

pub has_self_type: bool,

/// Associated type bindings like in `Iterator<Item = T>`.

- pub bindings: Vec<AssociatedTypeBinding>,

+ pub bindings: Box<[AssociatedTypeBinding]>,

/// Whether these generic args were desugared from `Trait(Arg) -> Output`

/// parenthesis notation typically used for the `Fn` traits.

pub desugared_from_fn: bool,

@@ -77,7 +77,7 @@ pub struct AssociatedTypeBinding {

/// Bounds for the associated type, like in `Iterator<Item:

/// SomeOtherTrait>`. (This is the unstable `associated_type_bounds`

/// feature.)

- pub bounds: Vec<Interned<TypeBound>>,

+ pub bounds: Box<[Interned<TypeBound>]>,

}

/// A single generic argument.

@@ -212,9 +212,9 @@ impl GenericArgs {

pub(crate) fn empty() -> GenericArgs {

GenericArgs {

- args: Vec::new(),

+ args: Box::default(),

has_self_type: false,

- bindings: Vec::new(),

+ bindings: Box::default(),

desugared_from_fn: false,

}

diff --git a/crates/hir-def/src/path/lower.rs b/crates/hir-def/src/path/lower.rs
index 334750a591..c85a11db6d 100644
--- a/crates/hir-def/src/path/lower.rs
+++ b/crates/hir-def/src/path/lower.rs

@@ -1,5 +1,7 @@

//! Transforms syntax into `Path` objects, ideally with accounting for hygiene

+use std::iter;

use crate::type_ref::ConstScalarOrPath;

use either::Either;

@@ -86,15 +88,26 @@ pub(super) fn lower_path(mut path: ast::Path, ctx: &LowerCtx<'_>) -> Option<Path

generic_args.resize(segments.len(), None);

}

+ let self_type = GenericArg::Type(self_type);

// Insert the type reference (T in the above example) as Self parameter for the trait

let last_segment = generic_args.get_mut(segments.len() - num_segments)?;

- let mut args_inner = match last_segment {

- Some(it) => it.as_ref().clone(),

- None => GenericArgs::empty(),

- };

- args_inner.has_self_type = true;

- args_inner.args.insert(0, GenericArg::Type(self_type));

- *last_segment = Some(Interned::new(args_inner));

+ *last_segment = Some(Interned::new(match last_segment.take() {

+ Some(it) => GenericArgs {

+ args: iter::once(self_type)

+ .chain(it.args.iter().cloned())

+ .collect(),

+ has_self_type: true,

+ bindings: it.bindings.clone(),

+ desugared_from_fn: it.desugared_from_fn,

+ },

+ None => GenericArgs {

+ args: Box::new([self_type]),

+ has_self_type: true,

+ ..GenericArgs::empty()

+ },

+ }));

}

@@ -187,7 +200,7 @@ pub(super) fn lower_generic_args(

.map(|it| Interned::new(TypeBound::from_ast(lower_ctx, it)))

.collect()

} else {

- Vec::new()

+ Box::default()

};

bindings.push(AssociatedTypeBinding { name, args, type_ref, bounds });

}

@@ -208,7 +221,12 @@ pub(super) fn lower_generic_args(

if args.is_empty() && bindings.is_empty() {

return None;

}

- Some(GenericArgs { args, has_self_type: false, bindings, desugared_from_fn: false })

+ Some(GenericArgs {

+ args: args.into_boxed_slice(),

+ has_self_type: false,

+ bindings: bindings.into_boxed_slice(),

+ desugared_from_fn: false,

+ })

}

/// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y)

@@ -218,33 +236,30 @@ fn lower_generic_args_from_fn_path(

params: Option<ast::ParamList>,

ret_type: Option<ast::RetType>,

) -> Option<GenericArgs> {

- let mut args = Vec::new();

- let mut bindings = Vec::new();

let params = params?;

let mut param_types = Vec::new();

for param in params.params() {

let type_ref = TypeRef::from_ast_opt(ctx, param.ty());

param_types.push(type_ref);

}

- let arg = GenericArg::Type(TypeRef::Tuple(param_types));

- args.push(arg);

- if let Some(ret_type) = ret_type {

+ let args = Box::new([GenericArg::Type(TypeRef::Tuple(param_types))]);

+ let bindings = if let Some(ret_type) = ret_type {

let type_ref = TypeRef::from_ast_opt(ctx, ret_type.ty());

- bindings.push(AssociatedTypeBinding {

+ Box::new([AssociatedTypeBinding {

args: None,

type_ref: Some(type_ref),

- bounds: Vec::new(),

- });

+ bounds: Box::default(),

+ }])

} else {

// -> ()

let type_ref = TypeRef::Tuple(Vec::new());

- bindings.push(AssociatedTypeBinding {

+ Box::new([AssociatedTypeBinding {

args: None,

type_ref: Some(type_ref),

- bounds: Vec::new(),

- });

- }

+ bounds: Box::default(),

+ }])

+ };

Some(GenericArgs { args, has_self_type: false, bindings, desugared_from_fn: true })

}

diff --git a/crates/hir-def/src/pretty.rs b/crates/hir-def/src/pretty.rs
index 1c0bd204d3..2d45c8c8da 100644
--- a/crates/hir-def/src/pretty.rs
+++ b/crates/hir-def/src/pretty.rs

@@ -71,7 +71,7 @@ pub(crate) fn print_generic_args(generics: &GenericArgs, buf: &mut dyn Write) ->

first = false;

print_generic_arg(arg, buf)?;

}

- for binding in &generics.bindings {

+ for binding in generics.bindings.iter() {

if !first {

write!(buf, ", ")?;

}

diff --git a/crates/hir-def/src/type_ref.rs b/crates/hir-def/src/type_ref.rs
index 8fa12c7aaf..9652b01b91 100644
--- a/crates/hir-def/src/type_ref.rs
+++ b/crates/hir-def/src/type_ref.rs

@@ -292,7 +292,7 @@ impl TypeRef {

}

for segment in path.segments().iter() {

if let Some(args_and_bindings) = segment.args_and_bindings {

- for arg in &args_and_bindings.args {

+ for arg in args_and_bindings.args.iter() {

match arg {

crate::path::GenericArg::Type(type_ref) => {

go(type_ref, f);

@@ -301,11 +301,11 @@ impl TypeRef {

| crate::path::GenericArg::Lifetime(_) => {}

}

- for binding in &args_and_bindings.bindings {

+ for binding in args_and_bindings.bindings.iter() {

if let Some(type_ref) = &binding.type_ref {

go(type_ref, f);

}

- for bound in &binding.bounds {

+ for bound in binding.bounds.iter() {

match bound.as_ref() {

TypeBound::Path(path, _) | TypeBound::ForLifetime(_, path) => {

go_path(path, f)

diff --git a/crates/hir-ty/src/display.rs b/crates/hir-ty/src/display.rs
index 5fcbdf34f3..b22064d8c4 100644
--- a/crates/hir-ty/src/display.rs
+++ b/crates/hir-ty/src/display.rs

@@ -1419,7 +1419,7 @@ impl HirDisplay for Path {

write!(f, "<")?;

let mut first = true;

- for arg in &generic_args.args {

+ for arg in generic_args.args.iter() {

if first {

first = false;

if generic_args.has_self_type {

@@ -1431,7 +1431,7 @@ impl HirDisplay for Path {

}

arg.hir_fmt(f)?;

}

- for binding in &generic_args.bindings {

+ for binding in generic_args.bindings.iter() {

if first {

first = false;

} else {

@@ -1445,7 +1445,7 @@ impl HirDisplay for Path {

}

None => {

write!(f, ": ")?;

- f.write_joined(&binding.bounds, " + ")?;

+ f.write_joined(binding.bounds.iter(), " + ")?;

}

diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs
index 7cce13a793..2996467372 100644
--- a/crates/hir-ty/src/lower.rs
+++ b/crates/hir-ty/src/lower.rs

@@ -1025,7 +1025,7 @@ impl<'a> TyLoweringContext<'a> {

last_segment

.into_iter()

.filter_map(|segment| segment.args_and_bindings)

- .flat_map(|args_and_bindings| &args_and_bindings.bindings)

+ .flat_map(|args_and_bindings| args_and_bindings.bindings.iter())

.flat_map(move |binding| {

let found = associated_type_by_name_including_super_traits(

self.db,

@@ -1068,7 +1068,7 @@ impl<'a> TyLoweringContext<'a> {

AliasEq { alias: AliasTy::Projection(projection_ty.clone()), ty };

preds.push(crate::wrap_empty_binders(WhereClause::AliasEq(alias_eq)));

}

- for bound in &binding.bounds {

+ for bound in binding.bounds.iter() {

preds.extend(self.lower_type_bound(

bound,

TyKind::Alias(AliasTy::Projection(projection_ty.clone())).intern(Interner),