Use our own Ready for IoAction to avoid bumping MSRV

std::future::Ready::into_inner requires 1.82, which is still fairly
recent.

src/ioaction.rs

@@ -57,8 +57,19 @@ pub mod blocking {
     }
 }
 
-impl<T> IoAction for std::future::Ready<T> {
+pub(crate) struct Ready<T>(pub(crate) T);
+
+impl<T> IntoFuture for Ready<T> {
+    type Output = T;
+    type IntoFuture = std::future::Ready<T>;
+
+    fn into_future(self) -> Self::IntoFuture {
+        std::future::ready(self.0)
+    }
+}
+
+impl<T> IoAction for Ready<T> {
     fn wait(self) -> Self::Output {
-        self.into_inner()
+        self.0
     }
 }

src/platform/linux_usbfs/enumeration.rs

@@ -8,7 +8,7 @@ use log::debug;
 use log::warn;
 
 use crate::enumeration::InterfaceInfo;
-use crate::ioaction::blocking::Blocking;
+use crate::ioaction::Ready;
 use crate::IoAction;
 use crate::{BusInfo, DeviceInfo, Error, Speed, UsbControllerType};
 
@@ -122,7 +122,7 @@ impl FromHexStr for u16 {
 const SYSFS_USB_PREFIX: &'static str = "/sys/bus/usb/devices/";
 
 pub fn list_devices() -> impl IoAction<Output = Result<impl Iterator<Item = DeviceInfo>, Error>> {
-    Blocking::new(move || {
+    Ready((|| {
         Ok(fs::read_dir(SYSFS_USB_PREFIX)?.flat_map(|entry| {
             let path = entry.ok()?.path();
             let name = path.file_name()?;
@@ -143,7 +143,7 @@ pub fn list_devices() -> impl IoAction<Output = Result<impl Iterator<Item = Devi
                 .inspect_err(|e| warn!("{e}; ignoring device"))
                 .ok()
         }))
-    })
+    })())
 }
 
 pub fn list_root_hubs() -> Result<impl Iterator<Item = DeviceInfo>, Error> {
@@ -163,7 +163,7 @@ pub fn list_root_hubs() -> Result<impl Iterator<Item = DeviceInfo>, Error> {
 }
 
 pub fn list_buses() -> impl IoAction<Output = Result<impl Iterator<Item = BusInfo>, Error>> {
-    Blocking::new(move || {
+    Ready((|| {
         Ok(list_root_hubs()?.filter_map(|rh| {
             // get the parent by following the absolute symlink; root hub in /bus/usb is a symlink to a dir in parent bus
             let parent_path = rh
@@ -186,7 +186,7 @@ pub fn list_buses() -> impl IoAction<Output = Result<impl Iterator<Item = BusInf
                 root_hub: rh,
             })
         }))
-    })
+    })())
 }
 
 pub fn probe_device(path: SysfsPath) -> Result<DeviceInfo, SysfsError> {

src/platform/macos_iokit/enumeration.rs

@@ -15,7 +15,7 @@ use io_kit_sys::{
 };
 use log::debug;
 
-use crate::{BusInfo, DeviceInfo, Error, InterfaceInfo, IoAction, Speed, UsbControllerType};
+use crate::{BusInfo, DeviceInfo, Error, InterfaceInfo, IoAction, Speed, UsbControllerType, ioaction::Ready};
 
 use super::iokit::{IoService, IoServiceIterator};
 /// IOKit class name for PCI USB XHCI high-speed controllers (USB 3.0+)
@@ -77,13 +77,13 @@ fn usb_controller_service_iter(
 }
 
 pub fn list_devices() -> impl IoAction<Output = Result<impl Iterator<Item = DeviceInfo>, Error>> {
-    std::future::ready(usb_service_iter().map(|i| i.filter_map(probe_device)))
+    Ready(usb_service_iter().map(|i| i.filter_map(probe_device)))
 }
 
 pub fn list_buses() -> impl IoAction<Output = Result<impl Iterator<Item = BusInfo>, Error>> {
     // Chain all the HCI types into one iterator
     // A bit of a hack, could maybe probe IOPCIDevice and filter on children with IOClass.starts_with("AppleUSB")
-    std::future::ready(Ok([
+    Ready(Ok([
         UsbControllerType::XHCI,
         UsbControllerType::EHCI,
         UsbControllerType::OHCI,

src/platform/windows_winusb/device.rs

@@ -24,7 +24,7 @@ use windows_sys::Win32::{
 
 use crate::{
     descriptors::{validate_config_descriptor, DESCRIPTOR_TYPE_CONFIGURATION},
-    ioaction::blocking::Blocking,
+    ioaction::{blocking::Blocking, Ready},
     transfer::{Control, Direction, EndpointType, Recipient, TransferError, TransferHandle},
     DeviceInfo, Error, IoAction,
 };
@@ -96,7 +96,7 @@ impl WindowsDevice {
         &self,
         _configuration: u8,
     ) -> impl IoAction<Output = Result<(), Error>> {
-        std::future::ready(Err(io::Error::new(
+        Ready(Err(io::Error::new(
             ErrorKind::Unsupported,
             "set_configuration not supported by WinUSB",
         )))
@@ -112,7 +112,7 @@ impl WindowsDevice {
     }
 
     pub(crate) fn reset(&self) -> impl IoAction<Output = Result<(), Error>> {
-        std::future::ready(Err(io::Error::new(
+        Ready(Err(io::Error::new(
             ErrorKind::Unsupported,
             "reset not supported by WinUSB",
         )))