diff --git a/src/cast.rs b/src/cast.rs
index 62e6bf6..2d7fe19 100644
--- a/src/cast.rs
+++ b/src/cast.rs
@@ -452,6 +452,74 @@ impl<T: NumCast> NumCast for Wrapping<T> {
     }
 }
 
+/// A generic interface for casting between machine scalars with the
+/// `as` operator, which admits narrowing and precision loss.
+/// Implementers of this trait AsPrimitive should behave like a primitive
+/// numeric type (e.g. a newtype around another primitive), and the
+/// intended conversion must never fail.
+///
+/// # Examples
+///
+/// ```
+/// # use num_traits::AsPrimitive;
+/// let three: i32 = (3.14159265f32).as_();
+/// assert_eq!(three, 3);
+/// ```
+/// 
+/// # Safety
+/// 
+/// Currently, some uses of the `as` operator are not entirely safe.
+/// In particular, it is undefined behavior if:
+/// 
+/// - A truncated floating point value cannot fit in the target integer
+///   type ([#10184](https://github.com/rust-lang/rust/issues/10184));
+/// 
+/// ```ignore
+/// # use num_traits::AsPrimitive;
+/// let x: u8 = (1.04E+17).as_(); // UB
+/// ```
+/// 
+/// - Or a floating point value does not fit in another floating
+///   point type ([#15536](https://github.com/rust-lang/rust/issues/15536)).
+///
+/// ```ignore
+/// # use num_traits::AsPrimitive;
+/// let x: f32 = (1e300f64).as_(); // UB
+/// ```
+/// 
+pub trait AsPrimitive<T>: 'static + Copy
+where
+    T: 'static + Copy
+{
+    /// Convert a value to another, using the `as` operator.
+    fn as_(self) -> T;
+}
+
+macro_rules! impl_as_primitive {
+    ($T: ty => $( $U: ty ),* ) => {
+        $(
+        impl AsPrimitive<$U> for $T {
+            #[inline] fn as_(self) -> $U { self as $U }
+        }
+        )*
+    };
+}
+
+impl_as_primitive!(u8 => char, u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(i8 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(u16 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(i16 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(u32 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(i32 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(u64 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(i64 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(usize => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(isize => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(f32 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(f64 => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64, f32, f64);
+impl_as_primitive!(char => char, u8, i8, u16, i16, u32, i32, u64, isize, usize, i64);
+impl_as_primitive!(bool => u8, i8, u16, i16, u32, i32, u64, isize, usize, i64);
+
 #[test]
 fn to_primitive_float() {
     use std::f32;
@@ -509,3 +577,15 @@ fn wrapping_is_numcast() {
     fn require_numcast<T: NumCast>(_: &T) {}
     require_numcast(&Wrapping(42));
 }
+
+#[test]
+fn as_primitive() {
+    let x: f32 = (1.625f64).as_();
+    assert_eq!(x, 1.625f32);
+
+    let x: f32 = (3.14159265358979323846f64).as_();
+    assert_eq!(x, 3.1415927f32);
+
+    let x: u8 = (768i16).as_();
+    assert_eq!(x, 0);
+}
diff --git a/src/ops/checked.rs b/src/ops/checked.rs
index 45e6716..95214a2 100644
--- a/src/ops/checked.rs
+++ b/src/ops/checked.rs
@@ -1,4 +1,4 @@
-use std::ops::{Add, Sub, Mul, Div};
+use std::ops::{Add, Sub, Mul, Div, Shl, Shr};
 
 /// Performs addition that returns `None` instead of wrapping around on
 /// overflow.
@@ -90,3 +90,73 @@ checked_impl!(CheckedDiv, checked_div, i32);
 checked_impl!(CheckedDiv, checked_div, i64);
 checked_impl!(CheckedDiv, checked_div, isize);
 
+/// Performs a left shift that returns `None` on overflow.
+pub trait CheckedShl: Sized + Shl<u32, Output=Self> {
+    /// Shifts a number to the left, checking for overflow. If overflow happens,
+    /// `None` is returned.
+    ///
+    /// ```
+    /// use num_traits::CheckedShl;
+    ///
+    /// let x: u16 = 0x0001;
+    ///
+    /// assert_eq!(CheckedShl::checked_shl(&x, 0),  Some(0x0001));
+    /// assert_eq!(CheckedShl::checked_shl(&x, 1),  Some(0x0002));
+    /// assert_eq!(CheckedShl::checked_shl(&x, 15), Some(0x8000));
+    /// assert_eq!(CheckedShl::checked_shl(&x, 16), None);
+    /// ```
+    fn checked_shl(&self, rhs: u32) -> Option<Self>;
+}
+
+macro_rules! checked_shift_impl {
+    ($trait_name:ident, $method:ident, $t:ty) => {
+        impl $trait_name for $t {
+            #[inline]
+            fn $method(&self, rhs: u32) -> Option<$t> {
+                <$t>::$method(*self, rhs)
+            }
+        }
+    }
+}
+
+checked_shift_impl!(CheckedShl, checked_shl, u8);
+checked_shift_impl!(CheckedShl, checked_shl, u16);
+checked_shift_impl!(CheckedShl, checked_shl, u32);
+checked_shift_impl!(CheckedShl, checked_shl, u64);
+checked_shift_impl!(CheckedShl, checked_shl, usize);
+
+checked_shift_impl!(CheckedShl, checked_shl, i8);
+checked_shift_impl!(CheckedShl, checked_shl, i16);
+checked_shift_impl!(CheckedShl, checked_shl, i32);
+checked_shift_impl!(CheckedShl, checked_shl, i64);
+checked_shift_impl!(CheckedShl, checked_shl, isize);
+
+/// Performs a right shift that returns `None` on overflow.
+pub trait CheckedShr: Sized + Shr<u32, Output=Self> {
+    /// Shifts a number to the left, checking for overflow. If overflow happens,
+    /// `None` is returned.
+    ///
+    /// ```
+    /// use num_traits::CheckedShr;
+    ///
+    /// let x: u16 = 0x8000;
+    ///
+    /// assert_eq!(CheckedShr::checked_shr(&x, 0),  Some(0x8000));
+    /// assert_eq!(CheckedShr::checked_shr(&x, 1),  Some(0x4000));
+    /// assert_eq!(CheckedShr::checked_shr(&x, 15), Some(0x0001));
+    /// assert_eq!(CheckedShr::checked_shr(&x, 16), None);
+    /// ```
+    fn checked_shr(&self, rhs: u32) -> Option<Self>;
+}
+
+checked_shift_impl!(CheckedShr, checked_shr, u8);
+checked_shift_impl!(CheckedShr, checked_shr, u16);
+checked_shift_impl!(CheckedShr, checked_shr, u32);
+checked_shift_impl!(CheckedShr, checked_shr, u64);
+checked_shift_impl!(CheckedShr, checked_shr, usize);
+
+checked_shift_impl!(CheckedShr, checked_shr, i8);
+checked_shift_impl!(CheckedShr, checked_shr, i16);
+checked_shift_impl!(CheckedShr, checked_shr, i32);
+checked_shift_impl!(CheckedShr, checked_shr, i64);
+checked_shift_impl!(CheckedShr, checked_shr, isize);