Remove TRACE_FIELD_COUNT

Author: Avi-D-coder

src/lib.rs

@@ -30,7 +30,6 @@ pub unsafe trait Mark<'o, 'n, O, N> {
 
 pub unsafe trait Trace {
     fn trace(t: &Self);
-    const TRACE_FIELD_COUNT: u8;
     const TRACE_TYPE_INFO: GcTypeInfo;
     const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8];
     fn trace_transitive_type_info(tti: &mut Tti);
@@ -165,7 +164,6 @@ unsafe impl<T> Immutable for Box<T> {}
 // If you only implement Mark and not Trace CHILD_TYPE_INFO will all be const None
 unsafe impl<T: Immutable> Trace for T {
     default fn trace(_: &T) {}
-    default const TRACE_FIELD_COUNT: u8 = 0;
     default const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     default const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = [None; 8];
     default fn trace_transitive_type_info(_: &mut Tti) {}
@@ -181,7 +179,6 @@ unsafe impl<'r, T: 'r + Immutable + Trace> Trace for Gc<'r, T> {
     fn trace(t: &Self) {
         Trace::trace(t.deref())
     }
-    const TRACE_FIELD_COUNT: u8 = 0;
     // A Gc<Gc<T>> is equvlent to Gc<T>
     const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<T>();
     const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = [
@@ -204,7 +201,6 @@ unsafe impl<'r, T: Immutable + Trace> Trace for Option<T> {
     default fn trace(t: &Self) {
         Trace::trace(t.deref())
     }
-    default const TRACE_FIELD_COUNT: u8 = 0;
     default const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     default const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = GcTypeInfo::one_child::<T>();
     default fn trace_transitive_type_info(tti: &mut Tti) {
@@ -217,23 +213,20 @@ unsafe impl<'r, T: Immutable + Trace + HasNoGc> Trace for Option<T> {
     fn trace(t: &Self) {
         Trace::trace(t.deref())
     }
-    const TRACE_FIELD_COUNT: u8 = 0;
     const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = [None; 8];
     fn trace_transitive_type_info(_: &mut Tti) {}
 }
 
 unsafe impl<T: Immutable + Trace> Trace for Box<T> {
     default fn trace(_: &Self) {}
-    default const TRACE_FIELD_COUNT: u8 = 0;
     default const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     default const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = [None; 8];
     default fn trace_transitive_type_info(_: &mut Tti) {}
 }
 
 unsafe impl<T: Immutable + Trace + HasNoGc> Trace for Box<T> {
     fn trace(_: &Self) {}
-    const TRACE_FIELD_COUNT: u8 = 0;
     const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     default const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = GcTypeInfo::one_child::<T>();
     fn trace_transitive_type_info(tti: &mut Tti) {
@@ -251,7 +244,6 @@ struct List<'r, T> {
 // These three impls will be derived with a procedural macro
 unsafe impl<'r, T: 'r + Trace + Immutable> Trace for List<'r, T> {
     fn trace(_: &List<'r, T>) {}
-    const TRACE_FIELD_COUNT: u8 = 0;
     const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] = [
         Some(GcTypeInfo::new::<T>()),
@@ -309,7 +301,6 @@ struct Foo<'r> {
 
 unsafe impl<'r> Trace for Foo<'r> {
     fn trace(_: &Foo<'r>) {}
-    const TRACE_FIELD_COUNT: u8 = 0;
     const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
     default const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] =
         GcTypeInfo::one_child::<Gc<'r, usize>>();
@@ -384,7 +375,6 @@ fn hidden_lifetime_test() {
     // This may not be trivail to implement as a proc macro
     unsafe impl<'a, 'b: 'a> Trace for Foo2<'a, 'b> {
         fn trace(_: &Foo2<'a, 'b>) {}
-        const TRACE_FIELD_COUNT: u8 = 0;
         const TRACE_TYPE_INFO: GcTypeInfo = GcTypeInfo::new::<Self>();
         const TRACE_CHILD_TYPE_INFO: [Option<GcTypeInfo>; 8] =
             GcTypeInfo::one_child::<Gc<'a, Bar<'b>>>();