Don't use generic DB where a concrete one will do

Author: matklad

crates/ra_assists/src/handlers/fill_match_arms.rs

@@ -2,7 +2,7 @@
 
 use std::iter;
 
-use hir::{db::HirDatabase, Adt, HasSource, Semantics};
+use hir::{Adt, HasSource, Semantics};
 use ra_syntax::ast::{self, edit::IndentLevel, make, AstNode, NameOwner};
 
 use crate::{Assist, AssistCtx, AssistId};
@@ -88,11 +88,7 @@ fn resolve_enum_def(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<
     })
 }
 
-fn build_pat(
-    db: &impl HirDatabase,
-    module: hir::Module,
-    var: hir::EnumVariant,
-) -> Option<ast::Pat> {
+fn build_pat(db: &RootDatabase, module: hir::Module, var: hir::EnumVariant) -> Option<ast::Pat> {
     let path = crate::ast_transform::path_to_ast(module.find_use_path(db, var.into())?);
 
     // FIXME: use HIR for this; it doesn't currently expose struct vs. tuple vs. unit variants though

crates/ra_ide/src/completion/presentation.rs

@@ -1,6 +1,6 @@
 //! This modules takes care of rendering various definitions as completion items.
 
-use hir::{db::HirDatabase, Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, StructKind, Type};
+use hir::{Docs, HasAttrs, HasSource, HirDisplay, ScopeDef, StructKind, Type};
 use join_to_string::join;
 use ra_syntax::ast::NameOwner;
 use test_utils::tested_by;
@@ -9,7 +9,10 @@ use crate::completion::{
     CompletionContext, CompletionItem, CompletionItemKind, CompletionKind, Completions,
 };
 
-use crate::display::{const_label, macro_label, type_label, FunctionSignature};
+use crate::{
+    display::{const_label, macro_label, type_label, FunctionSignature},
+    RootDatabase,
+};
 
 impl Completions {
     pub(crate) fn add_field(
@@ -300,7 +303,7 @@ impl Completions {
     }
 }
 
-fn is_deprecated(node: impl HasAttrs, db: &impl HirDatabase) -> bool {
+fn is_deprecated(node: impl HasAttrs, db: &RootDatabase) -> bool {
     node.attrs(db).by_key("deprecated").exists()
 }