4 files changed, 17 insertions, 31 deletions

diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index ba7b39a19..512676c99 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -15,6 +15,7 @@ arrayvec = "0.5.1"
 
 itertools = "0.9.0"
 
+stdx = { path = "../stdx" }
 ra_syntax = { path = "../ra_syntax" }
 ra_db = { path = "../ra_db" }
 ra_prof = { path = "../ra_prof" }
diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 04fd335fe..9222009fe 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -38,6 +38,7 @@ use ra_syntax::{
     AstNode,
 };
 use rustc_hash::FxHashSet;
+use stdx::impl_from;
 
 use crate::{
     db::{DefDatabase, HirDatabase},
@@ -142,8 +143,8 @@ pub enum ModuleDef {
     TypeAlias(TypeAlias),
     BuiltinType(BuiltinType),
 }
-impl_froms!(
-    ModuleDef: Module,
+impl_from!(
+    Module,
     Function,
     Adt(Struct, Enum, Union),
     EnumVariant,
@@ -152,6 +153,7 @@ impl_froms!(
     Trait,
     TypeAlias,
     BuiltinType
+    for ModuleDef
 );
 
 impl ModuleDef {
@@ -541,7 +543,7 @@ pub enum Adt {
     Union(Union),
     Enum(Enum),
 }
-impl_froms!(Adt: Struct, Union, Enum);
+impl_from!(Struct, Union, Enum for Adt);
 
 impl Adt {
     pub fn has_non_default_type_params(self, db: &dyn HirDatabase) -> bool {
@@ -584,7 +586,7 @@ pub enum VariantDef {
     Union(Union),
     EnumVariant(EnumVariant),
 }
-impl_froms!(VariantDef: Struct, Union, EnumVariant);
+impl_from!(Struct, Union, EnumVariant for VariantDef);
 
 impl VariantDef {
     pub fn fields(self, db: &dyn HirDatabase) -> Vec<Field> {
@@ -627,8 +629,7 @@ pub enum DefWithBody {
     Static(Static),
     Const(Const),
 }
-
-impl_froms!(DefWithBody: Function, Const, Static);
+impl_from!(Function, Const, Static for DefWithBody);
 
 impl DefWithBody {
     pub fn module(self, db: &dyn HirDatabase) -> Module {
@@ -930,14 +931,15 @@ pub enum GenericDef {
     // consts can have type parameters from their parents (i.e. associated consts of traits)
     Const(Const),
 }
-impl_froms!(
-    GenericDef: Function,
+impl_from!(
+    Function,
     Adt(Struct, Enum, Union),
     Trait,
     TypeAlias,
     ImplDef,
     EnumVariant,
     Const
+    for GenericDef
 );
 
 impl GenericDef {
@@ -1578,8 +1580,8 @@ pub enum AttrDef {
     MacroDef(MacroDef),
 }
 
-impl_froms!(
-    AttrDef: Module,
+impl_from!(
+    Module,
     Field,
     Adt(Struct, Enum, Union),
     EnumVariant,
@@ -1589,6 +1591,7 @@ impl_froms!(
     Trait,
     TypeAlias,
     MacroDef
+    for AttrDef
 );
 
 pub trait HasAttrs {
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 3364a822f..7d9b174b4 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -19,25 +19,6 @@
 
 #![recursion_limit = "512"]
 
-macro_rules! impl_froms {
-    ($e:ident: $($v:ident $(($($sv:ident),*))?),*$(,)?) => {
-        $(
-            impl From<$v> for $e {
-                fn from(it: $v) -> $e {
-                    $e::$v(it)
-                }
-            }
-            $($(
-                impl From<$sv> for $e {
-                    fn from(it: $sv) -> $e {
-                        $e::$v($v::$sv(it))
-                    }
-                }
-            )*)?
-        )*
-    }
-}
-
 mod semantics;
 pub mod db;
 mod source_analyzer;
diff --git a/crates/ra_hir/src/semantics/source_to_def.rs b/crates/ra_hir/src/semantics/source_to_def.rs
index 0e1d92fb3..42e5a1bdb 100644
--- a/crates/ra_hir/src/semantics/source_to_def.rs
+++ b/crates/ra_hir/src/semantics/source_to_def.rs
@@ -16,6 +16,7 @@ use ra_syntax::{
     match_ast, AstNode, SyntaxNode,
 };
 use rustc_hash::FxHashMap;
+use stdx::impl_from;
 
 use crate::{db::HirDatabase, InFile, MacroDefId};
 
@@ -255,8 +256,7 @@ pub(crate) enum ChildContainer {
     /// here the children generic parameters, and not, eg enum variants.
     GenericDefId(GenericDefId),
 }
-impl_froms! {
-    ChildContainer:
+impl_from! {
     DefWithBodyId,
     ModuleId,
     TraitId,
@@ -265,6 +265,7 @@ impl_froms! {
     VariantId,
     TypeAliasId,
     GenericDefId
+    for ChildContainer
 }
 
 impl ChildContainer {