}

let generic_params = db.generic_params(*self);

// For traits the first type index is `Self`, skip it.

if let GenericDefId::TraitId(_) = *self {

LocalLifetimeParamId, LocalTypeOrConstParamId, Lookup, TypeOrConstParamId, TypeParamId,

};

const SELF_PARAM_ID_IN_SELF: la_arena::Idx<TypeOrConstParamData> =

LocalTypeOrConstParamId::from_raw(RawIdx::from_u32(0));

/// Data about the generic parameters of a function, struct, impl, etc.

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

pub struct GenericParams {

}

impl ops::Index<LocalTypeOrConstParamId> for GenericParams {

TypeOrConstParam(LocalTypeOrConstParamId),

}

#[derive(Clone, Default)]

pub(crate) struct GenericParamsCollector {

pub(crate) type_or_consts: Arena<TypeOrConstParamData>,

}

}

}

w!(self, "<");

let mut first = true;

if !first {

w!(self, ", ");

}

self.print_attrs_of(AttrOwner::LifetimeParamData(parent, idx), " ");

w!(self, "{}", lt.name.display(self.db.upcast()));

}

if !first {

w!(self, ", ");

}

}

fn print_where_clause(&mut self, params: &GenericParams) -> bool {

return false;

}

w!(self, "\nwhere");

self.indented(|this| {

if i != 0 {

wln!(this, ",");

}

match target {

WherePredicateTypeTarget::TypeRef(ty) => this.print_type_ref(ty),

}

w!(this, ": ");

this.print_type_bounds(std::slice::from_ref(bound));

Scope::GenericParams { params, def } => Some((params, def)),

_ => None,

})

}

pub fn generic_def(&self) -> Option<GenericDefId> {

}

Scope::GenericParams { params, def: parent } => {

let parent = *parent;

if let Some(name) = &param.name() {

let id = TypeOrConstParamId { parent, local_id };

acc.add(

name,

ScopeDef::GenericParam(match data {

);

}

}

let id = LifetimeParamId { parent, local_id };

acc.add(&param.name, ScopeDef::GenericParam(id.into()))

}

db: &dyn DefDatabase,

) -> InFile<ArenaMap<LocalTypeOrConstParamId, Self::Value>> {

let generic_params = db.generic_params(*self);

let (file_id, generic_params_list) = self.file_id_and_params_of(db);

db: &dyn DefDatabase,

) -> InFile<ArenaMap<LocalLifetimeParamId, Self::Value>> {

let generic_params = db.generic_params(*self);

let (file_id, generic_params_list) = self.file_id_and_params_of(db);

TyKind::Placeholder(idx) => {

let id = from_placeholder_idx(db, *idx);

let generic_params = db.generic_params(id.parent);

match param_data {

TypeOrConstParamData::TypeParamData(p) => match p.provenance {

hir_def::generics::TypeParamProvenance::ArgumentImplTrait => {

//!

//! The layout for generics as expected by chalk are as follows:

//! - Optional Self parameter

//! - Lifetime parameters

//! - Parent parameters

//!

//! where parent follows the same scheme.

LocalLifetimeParamId, LocalTypeOrConstParamId, Lookup, TypeOrConstParamId, TypeParamId,

};

use intern::Interned;

use stdx::TupleExt;

use crate::{db::HirDatabase, lt_to_placeholder_idx, to_placeholder_idx, Interner, Substitution};

pub(crate) fn generics(db: &dyn DefDatabase, def: GenericDefId) -> Generics {

let parent_generics = parent_generic_def(db, def).map(|def| Box::new(generics(db, def)));

}

#[derive(Clone, Debug)]

pub(crate) struct Generics {

def: GenericDefId,

params: Interned<GenericParams>,

parent_generics: Option<Box<Generics>>,

}

impl<T> ops::Index<T> for Generics

self.params.iter_type_or_consts().map(from_toc_id(self)).map(TupleExt::head)

}

/// Iterate over the params followed by the parent params.

pub(crate) fn iter(

&self,

pub(crate) fn iter_self(

&self,

) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'_>)> + '_ {

}

/// Iterator over types and const params of parent.

&self,

) -> impl DoubleEndedIterator<Item = (GenericParamId, GenericParamDataRef<'_>)> + '_ {

self.parent_generics().into_iter().flat_map(|it| {

})

}

fn find_type_or_const_param(&self, param: TypeOrConstParamId) -> Option<usize> {

if param.parent == self.def {

let idx = param.local_id.into_raw().into_u32() as usize;

} else {

debug_assert_eq!(self.parent_generics().map(|it| it.def), Some(param.parent));

self.parent_generics()

fn find_lifetime(&self, lifetime: LifetimeParamId) -> Option<usize> {

if lifetime.parent == self.def {

let idx = lifetime.local_id.into_raw().into_u32() as usize;

} else {

debug_assert_eq!(self.parent_generics().map(|it| it.def), Some(lifetime.parent));

self.parent_generics()

type_params,

const_params,

_impl_trait_params,

) = self

.generics()

.expect("variable impl trait lowering must be in a generic def")

.provenance_split();

TyKind::BoundVar(BoundVar::new(

self.in_binders,

))

.intern(Interner)

}

// Order is

// - Optional Self parameter

// - Lifetime parameters

// - Parent parameters

let def_generics = generics(self.db.upcast(), def);

let (

let ty_error = || TyKind::Error.intern(Interner).cast(Interner);

let mut def_toc_iter = def_generics.iter_self_type_or_consts_id();

let fill_self_param = || {

if self_param {

let self_ty = explicit_self_ty.map(|x| x.cast(Interner)).unwrap_or_else(ty_error);

};

let mut had_explicit_args = false;

if let Some(&GenericArgs { ref args, has_self_type, .. }) = args_and_bindings {

} else {

};

for arg in args

.iter()

{

}

.iter()

{

}

} else {

fill_self_param();

}

_ => false,

};

let defaults = &*self.db.generic_defaults(def);

let (item, _parent) = defaults.split_at(item_len);

let parent_from = item_len - substs.len();

let mut rem =

def_generics.iter_id().skip(substs.len()).map(param_to_err).collect::<Vec<_>>();

// Fill in defaults for type/const params

// each default can depend on the previous parameters

let substs_so_far = Substitution::from_iter(

Interner,

);

substs.push(default_ty.clone().substitute(Interner, &substs_so_far));

}

substs.extend(rem.drain(parent_from..));

} else {

// Fill in remaining def params and parent params

substs.extend(def_generics.iter_id().skip(substs.len()).map(param_to_err));

}

})

.collect::<Vec<_>>();

let explicitly_unsized_tys = ctx.unsized_types.into_inner();

if let Some(implicitly_sized_predicates) =

implicitly_sized_clauses(db, def, &explicitly_unsized_tys, &subst, &resolver)

// returns None if def is a type arg

pub(crate) fn const_param_ty_query(db: &dyn HirDatabase, def: ConstParamId) -> Ty {

let parent_data = db.generic_params(def.parent());

let resolver = def.parent().resolver(db.upcast());

let ctx = TyLoweringContext::new(db, &resolver, def.parent().into());

match data {

},

MirLowerError::GenericArgNotProvided(id, subst) => {

let parent = id.parent;

writeln!(

f,

"Generic arg not provided for {}",

let generic_params = db.generic_params(trait_.into());

let trait_self = generic_params.trait_self_param();

generic_params

.filter_map(|pred| match pred {

WherePredicate::ForLifetime { target, bound, .. }

| WherePredicate::TypeBound { target, bound } => {

impl HirDisplay for TypeParam {

fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> {

let params = f.db.generic_params(self.id.parent());

let substs = TyBuilder::placeholder_subst(f.db, self.id.parent());

let krate = self.id.parent().krate(f.db).id;

let ty =

f: &mut HirFormatter<'_>,

) -> Result<(), HirDisplayError> {

let params = f.db.generic_params(def);

&& params

.filter_map(|it| it.1.type_param())

.all(|param| !matches!(param.provenance, TypeParamProvenance::TypeParamList))

{

f.write_str(", ")

}

};

delim(f)?;

write!(f, "{}", lifetime.name.display(f.db.upcast()))?;

}

if let Some(name) = &ty.name() {

match ty {

TypeOrConstParamData::TypeParamData(ty) => {

}

fn has_disaplayable_predicates(params: &Interned<GenericParams>) -> bool {

!matches!(

pred,

WherePredicate::TypeBound { target: WherePredicateTypeTarget::TypeOrConstParam(id), .. }

)

})

}

let is_unnamed_type_target =

|params: &Interned<GenericParams>, target: &WherePredicateTypeTarget| {

matches!(target,

)

};

let write_target = |target: &WherePredicateTypeTarget, f: &mut HirFormatter<'_>| match target {

WherePredicateTypeTarget::TypeRef(ty) => ty.hir_fmt(f),

Some(name) => write!(f, "{}", name.display(f.db.upcast())),

None => f.write_str("{unnamed}"),

},

_ => false,

};

while let Some(pred) = iter.next() {

if matches!(pred, TypeBound { target, .. } if is_unnamed_type_target(params, target)) {

continue;

}

let parent = impl_def.id.into();

let generic_params = db.generic_params(parent);

GenericParamId::LifetimeParamId(LifetimeParamId { parent, local_id })

});

let type_params = generic_params

resolver

.generic_params()

.and_then(|gp| {

// there should only be a single lifetime

// but `Arena` requires to use an iterator

.nth(0)

count_required_only: bool,

) -> usize {

db.generic_params(self.id.into())

.filter(|(_, ty)| !matches!(ty, TypeOrConstParamData::TypeParamData(ty) if ty.provenance != TypeParamProvenance::TypeParamList))

.filter(|(_, ty)| !count_required_only || !ty.has_default())

.count()

impl GenericDef {

pub fn params(self, db: &dyn HirDatabase) -> Vec<GenericParam> {

let generics = db.generic_params(self.into());

let toc = TypeOrConstParam { id: TypeOrConstParamId { parent: self.into(), local_id } };

match toc.split(db) {

Either::Left(it) => GenericParam::ConstParam(it),

pub fn lifetime_params(self, db: &dyn HirDatabase) -> Vec<LifetimeParam> {

let generics = db.generic_params(self.into());

generics

.map(|(local_id, _)| LifetimeParam {

id: LifetimeParamId { parent: self.into(), local_id },

})

pub fn type_or_const_params(self, db: &dyn HirDatabase) -> Vec<TypeOrConstParam> {

let generics = db.generic_params(self.into());

generics

.map(|(local_id, _)| TypeOrConstParam {

id: TypeOrConstParamId { parent: self.into(), local_id },

})

/// argument)?

pub fn is_implicit(self, db: &dyn HirDatabase) -> bool {

let params = db.generic_params(self.id.parent());

match data.type_param().unwrap().provenance {

hir_def::generics::TypeParamProvenance::TypeParamList => false,

hir_def::generics::TypeParamProvenance::TraitSelf

impl LifetimeParam {

pub fn name(self, db: &dyn HirDatabase) -> Name {

let params = db.generic_params(self.id.parent);

}

pub fn module(self, db: &dyn HirDatabase) -> Module {

pub fn name(self, db: &dyn HirDatabase) -> Name {

let params = db.generic_params(self.id.parent());

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

None => {

never!();

impl TypeOrConstParam {

pub fn name(self, db: &dyn HirDatabase) -> Name {

let params = db.generic_params(self.id.parent);

Some(n) => n.clone(),

_ => Name::missing(),

}

pub fn split(self, db: &dyn HirDatabase) -> Either<ConstParam, TypeParam> {

let params = db.generic_params(self.id.parent);

hir_def::generics::TypeOrConstParamData::TypeParamData(_) => {

Either::Right(TypeParam { id: TypeParamId::from_unchecked(self.id) })

}

pub fn as_type_param(self, db: &dyn HirDatabase) -> Option<TypeParam> {

let params = db.generic_params(self.id.parent);

hir_def::generics::TypeOrConstParamData::TypeParamData(_) => {

Some(TypeParam { id: TypeParamId::from_unchecked(self.id) })

}

pub fn as_const_param(self, db: &dyn HirDatabase) -> Option<ConstParam> {

let params = db.generic_params(self.id.parent);

hir_def::generics::TypeOrConstParamData::TypeParamData(_) => None,

hir_def::generics::TypeOrConstParamData::ConstParamData(_) => {

Some(ConstParam { id: ConstParamId::from_unchecked(self.id) })