#[stable(feature = "raw_os", since = "1.1.0")]
#[doc(no_inline)]
pub use core::ffi::c_void;
+
+/// Equivalent to C's `size_t` type, from `stddef.h` (or `cstddef` for C++).
+///
+/// This type is currently always [`usize`], however in the future there may be
+/// platforms where this is not the case.
+#[unstable(feature = "c_size_t", issue = "none")]
+pub type c_size_t = usize;
+
+/// Equivalent to C's `ssize_t` type, from `stddef.h` (or `cstddef` for C++).
+///
+/// This type is currently always [`isize`], however in the future there may be
+/// platforms where this is not the case.
+#[unstable(feature = "c_size_t", issue = "none")]
+pub type c_ssize_t = isize;