Implement AsRawHandle for Std* on Windows

src/libstd/sys/windows/ext/io.rs

@@ -15,6 +15,7 @@ use os::windows::raw;
 use net;
 use sys_common::{self, AsInner, FromInner, IntoInner};
 use sys;
+use io;
 use sys::c;
 
 /// Raw HANDLEs.
@@ -71,6 +72,27 @@ impl AsRawHandle for fs::File {
     }
 }
 
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawHandle for io::Stdin {
+    fn as_raw_handle(&self) -> RawHandle {
+        unsafe { c::GetStdHandle(c::STD_INPUT_HANDLE) } as RawHandle
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawHandle for io::Stdout {
+    fn as_raw_handle(&self) -> RawHandle {
+        unsafe { c::GetStdHandle(c::STD_OUTPUT_HANDLE) } as RawHandle
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawHandle for io::Stderr {
+    fn as_raw_handle(&self) -> RawHandle {
+        unsafe { c::GetStdHandle(c::STD_ERROR_HANDLE) } as RawHandle
+    }
+}
+
 #[stable(feature = "from_raw_os", since = "1.1.0")]
 impl FromRawHandle for fs::File {
     unsafe fn from_raw_handle(handle: RawHandle) -> fs::File {