Mention Share in the tutorial

diff --git a/src/doc/tutorial.md b/src/doc/tutorial.md
index cdb521b96c42f6409d8c0b73946fc24dea99083b..0a417a5a8bf11a40e867bb09ae06903946a17c6a 100644 (file)
--- a/src/doc/tutorial.md
+++ b/src/doc/tutorial.md
@@ -2095,6 +2095,10 @@ and may not be overridden:
 Types are sendable
 unless they contain managed boxes, managed closures, or references.
 
+* `Share` - Types that are *threadsafe*
+These are types that are safe to be used across several threads with access to
+a `&T` pointer. `MutexArc` is an example of a *sharable* type with internal mutable data.
+
 * `Freeze` - Constant (immutable) types.
 These are types that do not contain anything intrinsically mutable.
 Intrinsically mutable values include `Cell` in the standard library.