Make decl_module not require a return type for functions (#1230)

If no return type is specified, `Result` is added and
`Ok(())` is returned by default.

Closes: #1182

substrate/srml/council/src/motions.rs

@@ -21,7 +21,7 @@ use rstd::result;
 use codec::Compact;
 use substrate_primitives::u32_trait::Value as U32;
 use primitives::traits::{Hash, EnsureOrigin};
-use srml_support::dispatch::{Result, Dispatchable, Parameter};
+use srml_support::dispatch::{Dispatchable, Parameter};
 use srml_support::{StorageValue, StorageMap};
 use super::{Trait as CouncilTrait, Module as Council};
 use system::{self, ensure_signed};
@@ -68,7 +68,7 @@ decl_event!(
 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: <T as system::Trait>::Origin {
 		fn deposit_event() = default;
-		fn propose(origin, threshold: Compact<u32>, proposal: Box<<T as Trait>::Proposal>) -> Result {
+		fn propose(origin, threshold: Compact<u32>, proposal: Box<<T as Trait>::Proposal>) {
 			let who = ensure_signed(origin)?;
 			let threshold = threshold.into();
 
@@ -90,10 +90,9 @@ decl_module! {
 
 				Self::deposit_event(RawEvent::Proposed(who, index, proposal_hash, threshold));
 			}
-			Ok(())
 		}
 
-		fn vote(origin, proposal: T::Hash, index: Compact<ProposalIndex>, approve: bool) -> Result {
+		fn vote(origin, proposal: T::Hash, index: Compact<ProposalIndex>, approve: bool) {
 			let who = ensure_signed(origin)?;
 			let index = index.into();
 
@@ -154,8 +153,6 @@ decl_module! {
 				// update voting
 				<Voting<T>>::insert(&proposal, voting);
 			}
-
-			Ok(())
 		}
 	}
 }

substrate/srml/council/src/seats.rs

@@ -91,7 +91,7 @@ decl_module! {
 
 		/// Set candidate approvals. Approval slots stay valid as long as candidates in those slots
 		/// are registered.
-		fn set_approvals(origin, votes: Vec<bool>, index: Compact<VoteIndex>) -> Result {
+		fn set_approvals(origin, votes: Vec<bool>, index: Compact<VoteIndex>) {
 			let who = ensure_signed(origin)?;
 			let index: VoteIndex = index.into();
 
@@ -110,7 +110,6 @@ decl_module! {
 			}
 			<LastActiveOf<T>>::insert(&who, index);
 			<ApprovalsOf<T>>::insert(&who, votes);
-			Ok(())
 		}
 
 		/// Remove a voter. For it not to be a bond-consuming no-op, all approved candidate indices
@@ -124,7 +123,7 @@ decl_module! {
 			who: Address<T::AccountId, T::AccountIndex>,
 			who_index: Compact<u32>,
 			assumed_vote_index: Compact<VoteIndex>
-		) -> Result {
+		) {
 			let reporter = ensure_signed(origin)?;
 			let assumed_vote_index: VoteIndex = assumed_vote_index.into();
 
@@ -166,11 +165,10 @@ decl_module! {
 				<balances::Module<T>>::slash_reserved(&reporter, Self::voting_bond());
 				Self::deposit_event(RawEvent::BadReaperSlashed(reporter));
 			}
-			Ok(())
 		}
 
 		/// Remove a voter. All votes are cancelled and the voter deposit is returned.
-		fn retract_voter(origin, index: Compact<u32>) -> Result {
+		fn retract_voter(origin, index: Compact<u32>) {
 			let who = ensure_signed(origin)?;
 
 			ensure!(!Self::presentation_active(), "cannot retract when presenting");
@@ -183,13 +181,12 @@ decl_module! {
 
 			Self::remove_voter(&who, index, voters);
 			<balances::Module<T>>::unreserve(&who, Self::voting_bond());
-			Ok(())
 		}
 
 		/// Submit oneself for candidacy.
 		///
 		/// Account must have enough transferrable funds in it to pay the bond.
-		fn submit_candidacy(origin, slot: Compact<u32>) -> Result {
+		fn submit_candidacy(origin, slot: Compact<u32>) {
 			let who = ensure_signed(origin)?;
 
 			ensure!(!Self::is_a_candidate(&who), "duplicate candidate submission");
@@ -215,7 +212,6 @@ decl_module! {
 			}
 			<Candidates<T>>::put(candidates);
 			<CandidateCount<T>>::put(count as u32 + 1);
-			Ok(())
 		}
 
 		/// Claim that `signed` is one of the top Self::carry_count() + current_vote().1 candidates.
@@ -276,37 +272,33 @@ decl_module! {
 		/// Set the desired member count; if lower than the current count, then seats will not be up
 		/// election when they expire. If more, then a new vote will be started if one is not already
 		/// in progress.
-		fn set_desired_seats(count: Compact<u32>) -> Result {
+		fn set_desired_seats(count: Compact<u32>) {
 			let count: u32 = count.into();
 			<DesiredSeats<T>>::put(count);
-			Ok(())
 		}
 
 		/// Remove a particular member. A tally will happen instantly (if not already in a presentation
 		/// period) to fill the seat if removal means that the desired members are not met.
 		/// This is effective immediately.
-		fn remove_member(who: Address<T::AccountId, T::AccountIndex>) -> Result {
+		fn remove_member(who: Address<T::AccountId, T::AccountIndex>) {
 			let who = <balances::Module<T>>::lookup(who)?;
 			let new_council: Vec<(T::AccountId, T::BlockNumber)> = Self::active_council()
 				.into_iter()
 				.filter(|i| i.0 != who)
 				.collect();
 			<ActiveCouncil<T>>::put(new_council);
-			Ok(())
 		}
 
 		/// Set the presentation duration. If there is currently a vote being presented for, will
 		/// invoke `finalise_vote`.
-		fn set_presentation_duration(count: <T::BlockNumber as HasCompact>::Type) -> Result {
+		fn set_presentation_duration(count: <T::BlockNumber as HasCompact>::Type) {
 			<PresentationDuration<T>>::put(count.into());
-			Ok(())
 		}
 
 		/// Set the presentation duration. If there is current a vote being presented for, will
 		/// invoke `finalise_vote`.
-		fn set_term_duration(count: <T::BlockNumber as HasCompact>::Type) -> Result {
+		fn set_term_duration(count: <T::BlockNumber as HasCompact>::Type) {
 			<TermDuration<T>>::put(count.into());
-			Ok(())
 		}
 
 		fn on_finalise(n: T::BlockNumber) {

substrate/srml/council/src/voting.rs

@@ -35,7 +35,7 @@ decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 		fn deposit_event() = default;
 
-		fn propose(origin, proposal: Box<T::Proposal>) -> Result {
+		fn propose(origin, proposal: Box<T::Proposal>) {
 			let who = ensure_signed(origin)?;
 
 			let expiry = <system::Module<T>>::block_number() + Self::voting_period();
@@ -54,11 +54,9 @@ decl_module! {
 			<ProposalOf<T>>::insert(proposal_hash, *proposal);
 			<ProposalVoters<T>>::insert(proposal_hash, vec![who.clone()]);
 			<CouncilVoteOf<T>>::insert((proposal_hash, who.clone()), true);
-
-			Ok(())
 		}
 
-		fn vote(origin, proposal: T::Hash, approve: bool) -> Result {
+		fn vote(origin, proposal: T::Hash, approve: bool) {
 			let who = ensure_signed(origin)?;
 
 			ensure!(Self::is_councillor(&who), "only councillors may vote on council proposals");
@@ -67,10 +65,9 @@ decl_module! {
 				<ProposalVoters<T>>::mutate(proposal, |voters| voters.push(who.clone()));
 			}
 			<CouncilVoteOf<T>>::insert((proposal, who), approve);
-			Ok(())
 		}
 
-		fn veto(origin, proposal_hash: T::Hash) -> Result {
+		fn veto(origin, proposal_hash: T::Hash) {
 			let who = ensure_signed(origin)?;
 
 			ensure!(Self::is_councillor(&who), "only councillors may veto council proposals");
@@ -96,17 +93,14 @@ decl_module! {
 			for (c, _) in <Council<T>>::active_council() {
 				<CouncilVoteOf<T>>::remove((proposal_hash, c));
 			}
-			Ok(())
 		}
 
-		fn set_cooloff_period(blocks: <T::BlockNumber as HasCompact>::Type) -> Result {
+		fn set_cooloff_period(blocks: <T::BlockNumber as HasCompact>::Type) {
 			<CooloffPeriod<T>>::put(blocks.into());
-			Ok(())
 		}
 
-		fn set_voting_period(blocks: <T::BlockNumber as HasCompact>::Type) -> Result {
+		fn set_voting_period(blocks: <T::BlockNumber as HasCompact>::Type) {
 			<VotingPeriod<T>>::put(blocks.into());
-			Ok(())
 		}
 
 		fn on_finalise(n: T::BlockNumber) {