Let bindings are now available in const contexts

Author: oli-obk

src/const_eval.md

@@ -9,7 +9,7 @@ can be evaluated at compile-time.
 Certain forms of expressions, called constant expressions, can be evaluated at
 compile time. In [const contexts](#const-context), these are the only allowed
 expressions, and are always evaluated at compile time. In other places, such as
-[`let` statements](statements.html#let-statements), constant expressions *may*
+[let statement]s, constant expressions *may*
 be, but are not guaranteed to be, evaluated at compile time. Behaviors such as
 out of bounds [array indexing] or [overflow] are compiler errors if the value
 must be evaluated at compile time (i.e. in const contexts). Otherwise, these
@@ -40,6 +40,7 @@ to be ran.
 * [Cast] expressions, except pointer to address and
   function pointer to address casts.
 * Calls of const functions and const methods
+* [let statement]s and thus irrefutable [patterns]
 
 ## Const context
 
@@ -81,3 +82,5 @@ A _const context_ is one of the following:
 [dereference operator]: expressions/operator-expr.html#the-dereference-operator
 [grouped]:              expressions/grouped-expr.html
 [cast]:                 expressions/operator-expr.html#type-cast-expressions
+[let statement]: statements.html#let-statements
+[patterns]: patterns.html