events: Reintroduce *EventContent as trait aliases

crates/ruma-client-api/src/config/set_global_account_data.rs

@@ -7,7 +7,10 @@ pub mod v3 {
 
     use ruma_common::{
         api::ruma_api,
-        events::{AnyGlobalAccountDataEventContent, EventContent, GlobalAccountDataEventType},
+        events::{
+            AnyGlobalAccountDataEventContent, GlobalAccountDataEventContent,
+            GlobalAccountDataEventType,
+        },
         serde::Raw,
         UserId,
     };
@@ -60,7 +63,7 @@ pub mod v3 {
         /// `T`s [`Serialize`][serde::Serialize] implementation can fail.
         pub fn new<T>(data: &'a T, user_id: &'a UserId) -> serde_json::Result<Self>
         where
-            T: EventContent<EventType = GlobalAccountDataEventType>,
+            T: GlobalAccountDataEventContent,
         {
             Ok(Self {
                 user_id,

crates/ruma-client-api/src/config/set_room_account_data.rs

@@ -7,7 +7,9 @@ pub mod v3 {
 
     use ruma_common::{
         api::ruma_api,
-        events::{AnyRoomAccountDataEventContent, EventContent, RoomAccountDataEventType},
+        events::{
+            AnyRoomAccountDataEventContent, RoomAccountDataEventContent, RoomAccountDataEventType,
+        },
         serde::Raw,
         RoomId, UserId,
     };
@@ -68,7 +70,7 @@ pub mod v3 {
             user_id: &'a UserId,
         ) -> serde_json::Result<Self>
         where
-            T: EventContent<EventType = RoomAccountDataEventType>,
+            T: RoomAccountDataEventContent,
         {
             Ok(Self {
                 data: Raw::from_json(to_raw_json_value(data)?),

crates/ruma-client-api/src/message/send_message_event.rs

@@ -7,7 +7,7 @@ pub mod v3 {
 
     use ruma_common::{
         api::ruma_api,
-        events::{AnyMessageLikeEventContent, EventContent, MessageLikeEventType},
+        events::{AnyMessageLikeEventContent, MessageLikeEventContent, MessageLikeEventType},
         serde::Raw,
         EventId, RoomId, TransactionId,
     };
@@ -68,7 +68,7 @@ pub mod v3 {
             content: &'a T,
         ) -> serde_json::Result<Self>
         where
-            T: EventContent<EventType = MessageLikeEventType>,
+            T: MessageLikeEventContent,
         {
             Ok(Self {
                 room_id,

crates/ruma-client-api/src/state/send_state_event.rs

@@ -7,7 +7,7 @@ pub mod v3 {
 
     use ruma_common::{
         api::ruma_api,
-        events::{AnyStateEventContent, EventContent, StateEventType},
+        events::{AnyStateEventContent, StateEventContent, StateEventType},
         serde::{Incoming, Raw},
         EventId, RoomId,
     };
@@ -66,7 +66,7 @@ pub mod v3 {
             content: &'a T,
         ) -> serde_json::Result<Self>
         where
-            T: EventContent<EventType = StateEventType>,
+            T: StateEventContent,
         {
             Ok(Self {
                 room_id,

crates/ruma-common/src/events/content.rs

@@ -5,6 +5,11 @@ use serde_json::value::RawValue as RawJsonValue;
 
 use crate::serde::Raw;
 
+use super::{
+    EphemeralRoomEventType, GlobalAccountDataEventType, MessageLikeEventType,
+    RoomAccountDataEventType, StateEventType, ToDeviceEventType,
+};
+
 /// The base trait that all event content types implement.
 ///
 /// Use [`macros::EventContent`] to derive this traits. It is not meant to be implemented manually.
@@ -128,3 +133,46 @@ pub enum EventKind {
     /// Presence event kind.
     Presence,
 }
+
+macro_rules! trait_aliases {
+    // need to use `,` instead of `+` because (1) path can't be followed by `+`
+    // and (2) `+` can't be used as a separator since it's a repetition operator
+    ($(
+        $( #[doc = $docs:literal] )*
+        trait $id:ident = $( $def:path ),+;
+    )*) => {
+        $(
+            $( #[doc = $docs] )*
+            pub trait $id: $($def+)+ {}
+            impl<T: $($def+)+> $id for T {}
+        )*
+    }
+}
+
+trait_aliases! {
+    /// An alias for `EventContent<EventType = GlobalAccountDataEventType>`.
+    trait GlobalAccountDataEventContent = EventContent<EventType = GlobalAccountDataEventType>;
+
+    /// An alias for `EventContent<EventType = RoomAccountDataEventType>`.
+    trait RoomAccountDataEventContent = EventContent<EventType = RoomAccountDataEventType>;
+
+    /// An alias for `EventContent<EventType = EphemeralRoomEventType>`.
+    trait EphemeralRoomEventContent = EventContent<EventType = EphemeralRoomEventType>;
+
+    /// An alias for `EventContent<EventType = MessageLikeEventType>`.
+    trait MessageLikeEventContent = EventContent<EventType = MessageLikeEventType>;
+
+    /// An alias for `EventContent<EventType = MessageLikeEventType> + RedactedEventContent`.
+    trait RedactedMessageLikeEventContent =
+        EventContent<EventType = MessageLikeEventType>, RedactedEventContent;
+
+    /// An alias for `EventContent<EventType = StateEventType>`.
+    trait StateEventContent = EventContent<EventType = StateEventType>;
+
+    /// An alias for `EventContent<EventType = StateEventType> + RedactedEventContent`.
+    trait RedactedStateEventContent =
+        EventContent<EventType = StateEventType>, RedactedEventContent;
+
+    /// An alias for `EventContent<EventType = ToDeviceEventType>`.
+    trait ToDeviceEventContent = EventContent<EventType = ToDeviceEventType>;
+}

crates/ruma-common/src/events/kinds.rs

@@ -4,29 +4,30 @@ use ruma_macros::Event;
 use serde::{Deserialize, Serialize};
 
 use super::{
-    EphemeralRoomEventType, EventContent, GlobalAccountDataEventType, MessageLikeEventType,
+    EphemeralRoomEventContent, GlobalAccountDataEventContent, MessageLikeEventContent,
-    MessageLikeUnsigned, RedactedEventContent, RedactedUnsigned, RoomAccountDataEventType,
+    MessageLikeEventType, MessageLikeUnsigned, RedactedMessageLikeEventContent,
-    StateEventType, StateUnsigned, ToDeviceEventType,
+    RedactedStateEventContent, RedactedUnsigned, RoomAccountDataEventContent, StateEventContent,
+    StateEventType, StateUnsigned, ToDeviceEventContent,
 };
 use crate::{EventId, MilliSecondsSinceUnixEpoch, RoomId, UserId};
 
 /// A global account data event.
 #[derive(Clone, Debug, Event)]
-pub struct GlobalAccountDataEvent<C: EventContent<EventType = GlobalAccountDataEventType>> {
+pub struct GlobalAccountDataEvent<C: GlobalAccountDataEventContent> {
     /// Data specific to the event type.
     pub content: C,
 }
 
 /// A room account data event.
 #[derive(Clone, Debug, Event)]
-pub struct RoomAccountDataEvent<C: EventContent<EventType = RoomAccountDataEventType>> {
+pub struct RoomAccountDataEvent<C: RoomAccountDataEventContent> {
     /// Data specific to the event type.
     pub content: C,
 }
 
 /// An ephemeral room event.
 #[derive(Clone, Debug, Event)]
-pub struct EphemeralRoomEvent<C: EventContent<EventType = EphemeralRoomEventType>> {
+pub struct EphemeralRoomEvent<C: EphemeralRoomEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -36,7 +37,7 @@ pub struct EphemeralRoomEvent<C: EventContent<EventType = EphemeralRoomEventType
 
 /// An ephemeral room event without a `room_id`.
 #[derive(Clone, Debug, Event)]
-pub struct SyncEphemeralRoomEvent<C: EventContent<EventType = EphemeralRoomEventType>> {
+pub struct SyncEphemeralRoomEvent<C: EphemeralRoomEventContent> {
     /// Data specific to the event type.
     pub content: C,
 }
@@ -46,7 +47,7 @@ pub struct SyncEphemeralRoomEvent<C: EventContent<EventType = EphemeralRoomEvent
 /// `MessageLikeEvent` implements the comparison traits using only the `event_id` field, a sorted
 /// list would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct MessageLikeEvent<C: EventContent<EventType = MessageLikeEventType>> {
+pub struct MessageLikeEvent<C: MessageLikeEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -71,7 +72,7 @@ pub struct MessageLikeEvent<C: EventContent<EventType = MessageLikeEventType>> {
 /// `SyncMessageLikeEvent` implements the comparison traits using only the `event_id` field, a
 /// sorted list would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct SyncMessageLikeEvent<C: EventContent<EventType = MessageLikeEventType>> {
+pub struct SyncMessageLikeEvent<C: MessageLikeEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -93,9 +94,7 @@ pub struct SyncMessageLikeEvent<C: EventContent<EventType = MessageLikeEventType
 /// `RedactedMessageLikeEvent` implements the comparison traits using only the `event_id` field, a
 /// sorted list would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct RedactedMessageLikeEvent<
+pub struct RedactedMessageLikeEvent<C: RedactedMessageLikeEventContent> {
-    C: EventContent<EventType = MessageLikeEventType> + RedactedEventContent,
-> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -120,9 +119,7 @@ pub struct RedactedMessageLikeEvent<
 /// `RedactedSyncMessageLikeEvent` implements the comparison traits using only the `event_id` field,
 /// a sorted list would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct RedactedSyncMessageLikeEvent<
+pub struct RedactedSyncMessageLikeEvent<C: RedactedMessageLikeEventContent> {
-    C: EventContent<EventType = MessageLikeEventType> + RedactedEventContent,
-> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -144,7 +141,7 @@ pub struct RedactedSyncMessageLikeEvent<
 /// `StateEvent` implements the comparison traits using only the `event_id` field, a sorted list
 /// would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct StateEvent<C: EventContent<EventType = StateEventType>> {
+pub struct StateEvent<C: StateEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -175,7 +172,7 @@ pub struct StateEvent<C: EventContent<EventType = StateEventType>> {
 /// `SyncStateEvent` implements the comparison traits using only the `event_id` field, a sorted list
 /// would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct SyncStateEvent<C: EventContent<EventType = StateEventType>> {
+pub struct SyncStateEvent<C: StateEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -200,7 +197,7 @@ pub struct SyncStateEvent<C: EventContent<EventType = StateEventType>> {
 
 /// A stripped-down state event, used for previews of rooms the user has been invited to.
 #[derive(Clone, Debug, Event)]
-pub struct StrippedStateEvent<C: EventContent<EventType = StateEventType>> {
+pub struct StrippedStateEvent<C: StateEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -216,7 +213,7 @@ pub struct StrippedStateEvent<C: EventContent<EventType = StateEventType>> {
 
 /// A minimal state event, used for creating a new room.
 #[derive(Clone, Debug, Event)]
-pub struct InitialStateEvent<C: EventContent<EventType = StateEventType>> {
+pub struct InitialStateEvent<C: StateEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -235,7 +232,7 @@ pub struct InitialStateEvent<C: EventContent<EventType = StateEventType>> {
 /// `RedactedStateEvent` implements the comparison traits using only the `event_id` field, a sorted
 /// list would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct RedactedStateEvent<C: EventContent<EventType = StateEventType> + RedactedEventContent> {
+pub struct RedactedStateEvent<C: RedactedStateEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -266,9 +263,7 @@ pub struct RedactedStateEvent<C: EventContent<EventType = StateEventType> + Reda
 /// `RedactedSyncStateEvent` implements the comparison traits using only the `event_id` field, a
 /// sorted list would be sorted lexicographically based on the event's `EventId`.
 #[derive(Clone, Debug, Event)]
-pub struct RedactedSyncStateEvent<
+pub struct RedactedSyncStateEvent<C: RedactedStateEventContent> {
-    C: EventContent<EventType = StateEventType> + RedactedEventContent,
-> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -293,7 +288,7 @@ pub struct RedactedSyncStateEvent<
 
 /// An event sent using send-to-device messaging.
 #[derive(Clone, Debug, Event)]
-pub struct ToDeviceEvent<C: EventContent<EventType = ToDeviceEventType>> {
+pub struct ToDeviceEvent<C: ToDeviceEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -303,7 +298,7 @@ pub struct ToDeviceEvent<C: EventContent<EventType = ToDeviceEventType>> {
 
 /// The decrypted payload of an `m.olm.v1.curve25519-aes-sha2` event.
 #[derive(Clone, Debug, Event)]
-pub struct DecryptedOlmV1Event<C: EventContent<EventType = MessageLikeEventType>> {
+pub struct DecryptedOlmV1Event<C: MessageLikeEventContent> {
     /// Data specific to the event type.
     pub content: C,
 
@@ -329,7 +324,7 @@ pub struct OlmV1Keys {
 
 /// The decrypted payload of an `m.megolm.v1.aes-sha2` event.
 #[derive(Clone, Debug, Event)]
-pub struct DecryptedMegolmV1Event<C: EventContent<EventType = MessageLikeEventType>> {
+pub struct DecryptedMegolmV1Event<C: MessageLikeEventContent> {
     /// Data specific to the event type.
     pub content: C,
 

crates/ruma-common/src/events/unsigned.rs

@@ -4,7 +4,7 @@ use serde_json::{from_str as from_json_str, value::RawValue as RawJsonValue};
 
 #[cfg(feature = "unstable-msc2675")]
 use super::relation::Relations;
-use super::{room::redaction::SyncRoomRedactionEvent, EventContent, StateEventType};
+use super::{room::redaction::SyncRoomRedactionEvent, StateEventContent};
 use crate::{serde::Raw, TransactionId};
 
 /// Extra information about a message event that is not incorporated into the event's hash.
@@ -57,7 +57,7 @@ impl MessageLikeUnsigned {
 /// Extra information about a state event that is not incorporated into the event's hash.
 #[derive(Clone, Debug, Deserialize, Serialize)]
 #[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
-pub struct StateUnsigned<C: EventContent<EventType = StateEventType>> {
+pub struct StateUnsigned<C: StateEventContent> {
     /// The time in milliseconds that has elapsed since the event was sent.
     ///
     /// This field is generated by the local homeserver, and may be incorrect if the local time on
@@ -81,7 +81,7 @@ pub struct StateUnsigned<C: EventContent<EventType = StateEventType>> {
     pub relations: Option<Relations>,
 }
 
-impl<C: EventContent<EventType = StateEventType>> StateUnsigned<C> {
+impl<C: StateEventContent> StateUnsigned<C> {
     /// Create a new `Unsigned` with fields set to `None`.
     pub fn new() -> Self {
         Self {
@@ -118,7 +118,7 @@ impl<C: EventContent<EventType = StateEventType>> StateUnsigned<C> {
 ///
 /// Needs to be public for UI tests.
 #[doc(hidden)]
-impl<C: EventContent<EventType = StateEventType>> StateUnsigned<C> {
+impl<C: StateEventContent> StateUnsigned<C> {
     pub fn _from_parts(event_type: &str, object: &RawJsonValue) -> serde_json::Result<Self> {
         #[derive(Deserialize)]
         #[serde(bound = "")] // Disable default C: Deserialize bound
@@ -148,7 +148,7 @@ impl<C: EventContent<EventType = StateEventType>> StateUnsigned<C> {
 
     pub fn _map_prev_unsigned<T>(&self, f: impl FnOnce(&C) -> T) -> StateUnsigned<T>
     where
-        T: EventContent<EventType = StateEventType>,
+        T: StateEventContent,
     {
         StateUnsigned {
             age: self.age,
@@ -160,7 +160,7 @@ impl<C: EventContent<EventType = StateEventType>> StateUnsigned<C> {
     }
 }
 
-impl<C: EventContent<EventType = StateEventType>> Default for StateUnsigned<C> {
+impl<C: StateEventContent> Default for StateUnsigned<C> {
     fn default() -> Self {
         Self::new()
     }

crates/ruma-common/tests/events/ui/04-event-sanity-check.rs

@@ -4,14 +4,14 @@
 extern crate serde;
 
 use ruma_common::{
-    events::{EventContent, StateEventType, StateUnsigned},
+    events::{StateEventContent, StateUnsigned},
     EventId, MilliSecondsSinceUnixEpoch, RoomId, UserId,
 };
 use ruma_macros::Event;
 
 /// State event.
 #[derive(Clone, Debug, Event)]
-pub struct StateEvent<C: EventContent<EventType = StateEventType>> {
+pub struct StateEvent<C: StateEventContent> {
     pub content: C,
     pub event_id: Box<EventId>,
     pub sender: Box<UserId>,

crates/ruma-common/tests/events/ui/05-named-fields.rs

@@ -1,8 +1,8 @@
-use ruma_common::events::{EventContent, StateEventType};
+use ruma_common::events::StateEventContent;
 use ruma_macros::Event;
 
 /// State event.
 #[derive(Clone, Debug, Event)]
-pub struct StateEvent<C: EventContent<EventType = StateEventType>>(C);
+pub struct StateEvent<C: StateEventContent>(C);
 
 fn main() {}

crates/ruma-common/tests/events/ui/05-named-fields.stderr

@@ -1,5 +1,5 @@
 error: the `Event` derive only supports structs with named fields
  --> tests/events/ui/05-named-fields.rs:6:12
   |
-6 | pub struct StateEvent<C: EventContent<EventType = StateEventType>>(C);
+6 | pub struct StateEvent<C: StateEventContent>(C);
   |            ^^^^^^^^^^

crates/ruma-common/tests/events/ui/06-no-content-field.rs

@@ -1,9 +1,9 @@
-use ruma_common::events::{EventContent, StateEventType};
+use ruma_common::events::StateEventContent;
 use ruma_macros::Event;
 
 /// State event.
 #[derive(Clone, Debug, Event)]
-pub struct StateEvent<C: EventContent<EventType = StateEventType>> {
+pub struct StateEvent<C: StateEventContent> {
     pub not_content: C,
 }
 

crates/ruma-common/tests/events/ui/06-no-content-field.stderr

@@ -1,5 +1,5 @@
 error: struct must contain a `content` field
- --> $DIR/06-no-content-field.rs:5:24
+ --> tests/events/ui/06-no-content-field.rs:5:24
   |
 5 | #[derive(Clone, Debug, Event)]
   |                        ^^^^^