Fix std/no-std incompatibility

examples/test.rs

@@ -7,7 +7,7 @@
 //! ```
 
 
-use serde_json::io::{Write, Result, Error};
+use serde_json::io::{Write, Result, Error, ErrorKind};
 
 struct X {
 }
@@ -18,7 +18,7 @@ impl Write for X {
 	}
 
 	fn flush(&mut self) -> Result<()> {
-		Err(Error {})
+		Err(Error::new(ErrorKind::Other, "flush not implemented"))
 	}
 }
 

src/io/core.rs

@@ -14,7 +14,9 @@ pub enum ErrorKind {
 /// see [`std::io::Error`]
 // I/O errors can never occur in no-std mode. All our no-std I/O implementations
 // are infallible.
-pub struct Error;
+pub struct Error {
+    _priv: (),
+}
 
 impl Display for Error {
     fn fmt(&self, _formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -23,8 +25,9 @@ impl Display for Error {
 }
 
 impl Error {
-    pub(crate) fn new(_kind: ErrorKind, _error: &'static str) -> Error {
-        Error
+    /// see [`std::io::Error::new`]
+    pub fn new(_kind: ErrorKind, _error: &'static str) -> Error {
+        Error(())
     }
 }