upgrade to rust 1.42 for better unwrap() errors and use of matches!

docs/dev.md

@@ -5,7 +5,7 @@
 You will first need:
 
 - Standard dependencies: `bash`, `curl`, `unzip`, `gunzip`
-- Rust, at least 1.41. https://www.rust-lang.org/tools/install
+- Rust, at least 1.42. https://www.rust-lang.org/tools/install
 
 One-time setup:
 

sim/src/mechanics/driving.rs

@@ -1007,10 +1007,7 @@ impl DrivingSimState {
             if intersections
                 .get_accepted_agents(i)
                 .iter()
-                .any(|a| match a {
-                    AgentID::Car(_) => true,
-                    _ => false,
-                })
+                .any(|a| matches!(a, AgentID::Car(_)))
             {
                 return format!("someone's turning in {} still", i);
             }

sim/src/mechanics/walking.rs

@@ -570,14 +570,8 @@ impl Pedestrian {
                 PedState::WaitingToTurn(_, _) => Some(self.path.next_step().as_turn()),
                 _ => None,
             },
-            preparing_bike: match self.state {
-                PedState::StartingToBike(_, _, _) | PedState::FinishingBiking(_, _, _) => true,
-                _ => false,
-            },
-            waiting_for_bus: match self.state {
-                PedState::WaitingForBus(_, _) => true,
-                _ => false,
-            },
+            preparing_bike: matches!(self.state, PedState::StartingToBike(_, _, _) | PedState::FinishingBiking(_, _, _)),
+            waiting_for_bus: matches!(self.state, PedState::WaitingForBus(_, _)),
             on,
             metadata: self.metadata(now),
         }

sim/src/trips.rs

@@ -613,11 +613,7 @@ impl Trip {
     }
 
     fn is_bus_trip(&self) -> bool {
-        self.legs.len() == 1
-            && match self.legs[0] {
-                TripLeg::ServeBusRoute(_, _) => true,
-                _ => false,
-            }
+        self.legs.len() == 1 && matches!(self.legs[0], TripLeg::ServeBusRoute(_, _))
     }
 
     // Returns true if this succeeds. If not, trip aborted.