From 5ee2b8742a53e93c5b6a7ca48a338096864c8d1f Mon Sep 17 00:00:00 2001
From: Peter Huene <peter@huene.dev>
Date: Wed, 3 Mar 2021 13:27:56 -0800
Subject: [PATCH] Have `new_with_stack` impls return `io::Result`.

---
 crates/fiber/src/lib.rs     | 2 +-
 crates/fiber/src/unix.rs    | 4 ++--
 crates/fiber/src/windows.rs | 6 +++---
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/crates/fiber/src/lib.rs b/crates/fiber/src/lib.rs
index 6c835c511f..9a8d057f35 100644
--- a/crates/fiber/src/lib.rs
+++ b/crates/fiber/src/lib.rs
@@ -66,7 +66,7 @@ impl<'a, Resume, Yield, Return> Fiber<'a, Resume, Yield, Return> {
         func: impl FnOnce(Resume, &Suspend<Resume, Yield, Return>) -> Return + 'a,
     ) -> io::Result<Fiber<'a, Resume, Yield, Return>> {
         Ok(Fiber {
-            inner: imp::Fiber::new_with_stack(top_of_stack, func),
+            inner: imp::Fiber::new_with_stack(top_of_stack, func)?,
             done: Cell::new(false),
             _phantom: PhantomData,
         })
diff --git a/crates/fiber/src/unix.rs b/crates/fiber/src/unix.rs
index c14a188f50..0cc57ca319 100644
--- a/crates/fiber/src/unix.rs
+++ b/crates/fiber/src/unix.rs
@@ -75,7 +75,7 @@ impl Fiber {
         Ok(fiber)
     }
 
-    pub fn new_with_stack<F, A, B, C>(top_of_stack: *mut u8, func: F) -> Self
+    pub fn new_with_stack<F, A, B, C>(top_of_stack: *mut u8, func: F) -> io::Result<Self>
     where
         F: FnOnce(A, &super::Suspend<A, B, C>) -> C,
     {
@@ -86,7 +86,7 @@ impl Fiber {
 
         fiber.init(func);
 
-        fiber
+        Ok(fiber)
     }
 
     fn init<F, A, B, C>(&self, func: F)
diff --git a/crates/fiber/src/windows.rs b/crates/fiber/src/windows.rs
index c40fb8aeb0..b2d657eb88 100644
--- a/crates/fiber/src/windows.rs
+++ b/crates/fiber/src/windows.rs
@@ -3,6 +3,7 @@ use std::cell::Cell;
 use std::io;
 use std::ptr;
 use winapi::shared::minwindef::*;
+use winapi::shared::winerror::ERROR_NOT_SUPPORTED;
 use winapi::um::fibersapi::*;
 use winapi::um::winbase::*;
 
@@ -66,12 +67,11 @@ impl Fiber {
         }
     }
 
-    pub fn new_with_stack<F, A, B, C>(_top_of_stack: *mut u8, _func: F) -> Self
+    pub fn new_with_stack<F, A, B, C>(_top_of_stack: *mut u8, _func: F) -> io::Result<Self>
     where
         F: FnOnce(A, &super::Suspend<A, B, C>) -> C,
     {
-        // Windows fibers have no support for custom stacks
-        unimplemented!()
+        Err(io::Error::from_raw_os_error(ERROR_NOT_SUPPORTED as i32))
     }
 
     pub(crate) fn resume<A, B, C>(&self, result: &Cell<RunResult<A, B, C>>) {