Move cold panic functions in Option and Result

Move functions out of their impl blocks; avoids unnecessary monomorphization by type parameters that are irrelevant to the message output.

Author: bluss

src/libcore/option.rs

@@ -295,16 +295,10 @@ impl<T> Option<T> {
  pub fn expect(self, msg: &str) -> T {
  match self {
  Some(val) => val,
- None => Self::expect_failed(msg),
+ None => expect_failed(msg),
  }
  }
 
- #[inline(never)]
- #[cold]
- fn expect_failed(msg: &str) -> ! {
- panic!("{}", msg)
- }
-
  /// Moves the value `v` out of the `Option<T>` if it is `Some(v)`.
  ///
  /// # Panics
@@ -703,6 +697,14 @@ impl<T: Default> Option<T> {
  }
 }
 
+// This is a separate function to reduce the code size of .expect() itself.
+#[inline(never)]
+#[cold]
+fn expect_failed(msg: &str) -> ! {
+ panic!("{}", msg)
+}
+
+
 /////////////////////////////////////////////////////////////////////////////
 // Trait implementations
 /////////////////////////////////////////////////////////////////////////////

src/libcore/result.rs

@@ -684,16 +684,10 @@ impl<T, E: fmt::Debug> Result<T, E> {
  pub fn unwrap(self) -> T {
  match self {
  Ok(t) => t,
- Err(e) => Self::unwrap_failed(e),
+ Err(e) => unwrap_failed("called `Result::unwrap()` on an `Err` value", e),
  }
  }
 
- #[inline(never)]
- #[cold]
- fn unwrap_failed(error: E) -> ! {
- panic!("called `Result::unwrap()` on an `Err` value: {:?}", error)
- }
-
  /// Unwraps a result, yielding the content of an `Ok`.
  ///
  /// # Panics
@@ -711,15 +705,9 @@ impl<T, E: fmt::Debug> Result<T, E> {
  pub fn expect(self, msg: &str) -> T {
  match self {
  Ok(t) => t,
- Err(e) => Self::expect_failed(msg, e),
+ Err(e) => unwrap_failed(msg, e),
  }
  }
-
- #[inline(never)]
- #[cold]
- fn expect_failed(msg: &str, error: E) -> ! {
- panic!("{}: {:?}", msg, error)
- }
 }
 
 impl<T: fmt::Debug, E> Result<T, E> {
@@ -745,17 +733,17 @@ impl<T: fmt::Debug, E> Result<T, E> {
  #[stable(feature = "rust1", since = "1.0.0")]
  pub fn unwrap_err(self) -> E {
  match self {
- Ok(t) => Self::unwrap_err_failed(t),
+ Ok(t) => unwrap_failed("called `Result::unwrap_err()` on an `Ok` value", t),
  Err(e) => e,
  }
  }
+}
 
- #[inline(never)]
- #[cold]
- fn unwrap_err_failed(t: T) -> ! {
- panic!("called `Result::unwrap_err()` on an `Ok` value: {:?}", t)
- }
-
+// This is a separate function to reduce the code size of the methods
+#[inline(never)]
+#[cold]
+fn unwrap_failed<E: fmt::Debug>(msg: &str, error: E) -> ! {
+ panic!("{}: {:?}", msg, error)
 }
 
 /////////////////////////////////////////////////////////////////////////////