Improve fees module (#1821)

* remove amount associated
* make a new trait to bound some arithmetics to balances or assets:
  It also remove arithmetic bounds of srml-support::traits::Currency.

  To update your code then use srml_support::traits::ArithmeticType like:
  `type Currency: ArithmeticType + Currency<Self::AccountId, Balance=BalanceOf<Self>>; ` 
  with `type BalanceOf<T> = <<T as Trait>::Currency as ArithmeticType>::Type; `

* improve decl_storage when it explicit serde bound: basically don't try to be smarter than rust and just use where clause.

substrate/srml/support/procedural/src/storage/transformation.rs

@@ -192,13 +192,10 @@ fn decl_store_extra_genesis(
 				is_trait_needed = true;
 				has_trait_field = true;
 			}
-			for t in ext::get_non_bound_serde_derive_types(type_infos.value_type, &traitinstance) {
-				serde_complete_bound.insert(t);
-			}
+
+			serde_complete_bound.insert(type_infos.value_type);
 			if let DeclStorageTypeInfosKind::Map { key_type, .. } = type_infos.kind {
-				for t in ext::get_non_bound_serde_derive_types(key_type, &traitinstance) {
-					serde_complete_bound.insert(t);
-				}
+				serde_complete_bound.insert(key_type);
 			}
 			let storage_type = type_infos.typ.clone();
 			config_field.extend(match type_infos.kind {
@@ -285,9 +282,7 @@ fn decl_store_extra_genesis(
 						has_trait_field = true;
 					}
 
-					for t in ext::get_non_bound_serde_derive_types(extra_type, &traitinstance).into_iter() {
-						serde_complete_bound.insert(t);
-					}
+					serde_complete_bound.insert(extra_type);
 
 					let extrafield = &extra_field.content;
 					genesis_extrafields.extend(quote!{
@@ -315,6 +310,7 @@ fn decl_store_extra_genesis(
 	let serde_bug_bound = if !serde_complete_bound.is_empty() {
 		let mut b_ser = String::new();
 		let mut b_dser = String::new();
+		// panic!("{:#?}", serde_complete_bound);
 		serde_complete_bound.into_iter().for_each(|bound| {
 			let stype = quote!(#bound);
 			b_ser.push_str(&format!("{} : {}::serde::Serialize, ", stype, scrate));

substrate/srml/support/procedural/tools/src/syn_ext.rs

@@ -327,57 +327,3 @@ pub fn has_parametric_type_def(typ: &syn::Type, ident: &Ident, default: bool) ->
 pub fn has_parametric_type(typ: &syn::Type, ident: &Ident) -> bool {
 	has_parametric_type_def(typ, ident, true)
 }
-
-/// Get case where serde does not include bound with serde_derive macros:
-/// see https://github.com/serde-rs/serde/issues/1454
-pub fn get_non_bound_serde_derive_types(typ: &syn::Type, t: &syn::Ident) -> Vec<syn::Type> {
-	let mut result = Vec::new();
-	get_non_bound_serde_derive_types_inner(typ, t, &mut result);
-	result
-}
-
-fn get_non_bound_serde_derive_types_inner(typ: &syn::Type, t: &syn::Ident, result: &mut Vec<syn::Type>) {
-	match *typ {
-		syn::Type::Path(ref path) => {
-			if heuristic_is_associated_path(&path.path,t) {
-					result.push(typ.clone());
-			}
-			for p in path.path.segments.iter() {
-				if let syn::PathArguments::AngleBracketed(ref args) = p.arguments {
-					for a in args.args.iter() {
-						if let syn::GenericArgument::Type(ref ty) = a {
-							get_non_bound_serde_derive_types_inner(ty, t, result)
-						}
-					}
-				}
-			}
-		},
-		syn::Type::Slice(ref inner) => get_non_bound_serde_derive_types_inner(&inner.elem, t, result),
-		syn::Type::Array(ref inner) => get_non_bound_serde_derive_types_inner(&inner.elem, t, result),
-		syn::Type::Ptr(ref inner) => get_non_bound_serde_derive_types_inner(&inner.elem, t, result),
-		syn::Type::Reference(ref inner) => get_non_bound_serde_derive_types_inner(&inner.elem, t, result),
-		syn::Type::BareFn(..) => (),
-		syn::Type::Never(..) => (),
-		syn::Type::Tuple(ref inner) => for e in inner.elems.iter() {
-			get_non_bound_serde_derive_types_inner(e, t, result)
-		},
-		syn::Type::TraitObject(..) => (),
-		syn::Type::ImplTrait(..) => (),
-		syn::Type::Paren(ref inner) => get_non_bound_serde_derive_types_inner(&inner.elem, t, result),
-		syn::Type::Group(ref inner) => get_non_bound_serde_derive_types_inner(&inner.elem, t, result),
-		syn::Type::Infer(..) => (),
-		syn::Type::Macro(..) => (),
-		syn::Type::Verbatim(..) => (),
-	}
-
-}
-
-fn heuristic_is_associated_path(path: &syn::Path,t: &syn::Ident) -> bool {
-
-	if let Some(syn::punctuated::Pair::Punctuated(s,_)) = path.segments.first() {
-		&s.ident == t
-	} else {
-		false
-	}
-
-}

substrate/srml/support/src/traits.rs

@@ -79,10 +79,14 @@ pub enum UpdateBalanceOutcome {
 	AccountKilled,
 }
 
+pub trait ArithmeticType {
+	type Type: SimpleArithmetic + As<usize> + As<u64> + Codec + Copy + MaybeSerializeDebug + Default;
+}
+
 /// Abstraction over a fungible assets system.
 pub trait Currency<AccountId> {
 	/// The balance of an account.
-	type Balance: SimpleArithmetic + As<usize> + As<u64> + Codec + Copy + MaybeSerializeDebug + Default;
+	type Balance;
 
 	// PUBLIC IMMUTABLES