Add more from the std

crates/std/src/io.rs

@@ -21,7 +21,7 @@ pub fn stdin() -> Stdin {
     Stdin
 }
 
-pub type Result<T> = core::result::Result<T, ()>;
+pub type Result<T> = core::result::Result<T, Error>;
 
 pub(super) struct Repr();
 
@@ -30,10 +30,42 @@ pub(super) struct Repr();
 #[unstable(feature = "io_const_error", issue = "133448")]
 #[allow_internal_unstable(hint_must_use, io_const_error_internals)]
 pub macro const_error($kind:expr, $message:expr $(,)?) {
-    ()
+    crate::io::Error::new()
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Error {
     repr: Repr,
 }
+
+impl Error {
+    pub const fn new() -> Self {
+        Self { repr: Repr() }
+    }
+}
+
+#[allow(dead_code)]
+impl Error {
+    pub(crate) const INVALID_UTF8: Self =
+        const_error!(ErrorKind::InvalidData, "stream did not contain valid UTF-8");
+
+    pub(crate) const READ_EXACT_EOF: Self =
+        const_error!(ErrorKind::UnexpectedEof, "failed to fill whole buffer");
+
+    pub(crate) const UNKNOWN_THREAD_COUNT: Self = const_error!(
+        ErrorKind::NotFound,
+        "the number of hardware threads is not known for the target platform",
+    );
+
+    pub(crate) const UNSUPPORTED_PLATFORM: Self =
+        const_error!(ErrorKind::Unsupported, "operation not supported on this platform");
+
+    pub(crate) const WRITE_ALL_EOF: Self =
+        const_error!(ErrorKind::WriteZero, "failed to write whole buffer");
+
+    pub(crate) const ZERO_TIMEOUT: Self =
+        const_error!(ErrorKind::InvalidInput, "cannot set a 0 duration timeout");
+
+    pub(crate) const NO_ADDRESSES: Self =
+        const_error!(ErrorKind::InvalidInput, "could not resolve to any addresses");
+}