Add #[must_use] to all futures

embassy-rp/src/dma.rs

@@ -151,6 +151,7 @@ fn copy_inner<'a, C: Channel>(
     Transfer::new(ch)
 }
 
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Transfer<'a, C: Channel> {
     channel: PeripheralRef<'a, C>,
 }

embassy-rp/src/gpio.rs

@@ -193,6 +193,7 @@ unsafe fn IO_IRQ_BANK0() {
     }
 }
 
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 struct InputFuture<'a, T: Pin> {
     pin: PeripheralRef<'a, T>,
     level: InterruptTrigger,

embassy-rp/src/pio.rs

@@ -120,6 +120,7 @@ unsafe fn PIO1_IRQ_0() {
 }
 
 /// Future that waits for TX-FIFO to become writable
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct FifoOutFuture<'a, PIO: PioInstance, SM: PioStateMachine + Unpin> {
     sm: &'a mut SM,
     pio: PhantomData<PIO>,
@@ -182,6 +183,7 @@ impl<'d, PIO: PioInstance, SM: PioStateMachine + Unpin> Drop for FifoOutFuture<'
 }
 
 /// Future that waits for RX-FIFO to become readable
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct FifoInFuture<'a, PIO: PioInstance, SM: PioStateMachine> {
     sm: &'a mut SM,
     pio: PhantomData<PIO>,
@@ -241,6 +243,7 @@ impl<'d, PIO: PioInstance, SM: PioStateMachine> Drop for FifoInFuture<'d, PIO, S
 }
 
 /// Future that waits for IRQ
+#[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct IrqFuture<PIO: PioInstance> {
     pio: PhantomData<PIO>,
     irq_no: u8,