Remove Error::ToLuaConversionError

This variant used only once and not practically useful.

src/conversion.rs

@@ -6,7 +6,7 @@ use std::os::raw::c_int;
 use std::path::{Path, PathBuf};
 use std::{mem, slice, str};
 
-use bstr::{BStr, BString, ByteSlice, ByteVec};
+use bstr::{BStr, BString, ByteVec};
 use num_traits::cast;
 
 use crate::error::{Error, Result};
@@ -730,14 +730,17 @@ impl FromLua for OsString {
 }
 
 impl IntoLua for &OsStr {
+    #[cfg(unix)]
     #[inline]
     fn into_lua(self, lua: &Lua) -> Result<Value> {
-        let s = <[u8]>::from_os_str(self).ok_or_else(|| Error::ToLuaConversionError {
-            from: "OsStr".into(),
-            to: "string",
-            message: Some("invalid utf-8 encoding".into()),
-        })?;
-        Ok(Value::String(lua.create_string(s)?))
+        use std::os::unix::ffi::OsStrExt;
+        Ok(Value::String(lua.create_string(self.as_bytes())?))
+    }
+
+    #[cfg(not(unix))]
+    #[inline]
+    fn into_lua(self, lua: &Lua) -> Result<Value> {
+        self.display().to_string().into_lua(lua)
     }
 }
 

src/error.rs

@@ -87,15 +87,6 @@ pub enum Error {
         /// Underlying error returned when converting argument to a Lua value.
         cause: Arc<Error>,
     },
-    /// A Rust value could not be converted to a Lua value.
-    ToLuaConversionError {
-        /// Name of the Rust type that could not be converted.
-        from: String,
-        /// Name of the Lua type that could not be created.
-        to: &'static str,
-        /// A message indicating why the conversion failed in more detail.
-        message: Option<String>,
-    },
     /// A Lua value could not be converted to the expected Rust type.
     FromLuaConversionError {
         /// Name of the Lua type that could not be converted.
@@ -249,13 +240,6 @@ impl fmt::Display for Error {
                 }
                 write!(fmt, ": {cause}")
             }
-            Error::ToLuaConversionError { from, to, message } => {
-                write!(fmt, "error converting {from} to Lua {to}")?;
-                match message {
-                    None => Ok(()),
-                    Some(message) => write!(fmt, " ({message})"),
-                }
-            }
             Error::FromLuaConversionError { from, to, message } => {
                 write!(fmt, "error converting Lua {from} to {to}")?;
                 match message {