Consider proc as a pointer type in options (#13460)

* Consider proc as a pointer type in options

* Add version annotation for SomePointer having proc in options

* Log procs as pointers for options in changelog

changelog.md

@@ -25,6 +25,8 @@
   It didn't work well together with the existing inplace version of the same proc
   (`tables.merge(var CountTable, CountTable)`).
   It was an oversight to be included in v1.0.
+- `options` now treats `proc` like other pointer types, meaning `nil` proc variables
+  are converted to `None`.
 
 
 ### Breaking changes in the compiler

lib/pure/options.nim

@@ -58,8 +58,12 @@
 
 import typetraits
 
-type
-  SomePointer = ref | ptr | pointer
+when (NimMajor, NimMinor) >= (1, 1):
+  type
+    SomePointer = ref | ptr | pointer | proc
+else:
+  type
+    SomePointer = ref | ptr | pointer
 
 type
   Option*[T] = object
@@ -74,7 +78,7 @@ type
 
 
 proc option*[T](val: T): Option[T] =
-  ## Can be used to convert a pointer type (`ptr` or `ref`) to an option type.
+  ## Can be used to convert a pointer type (`ptr` or `ref` or `proc`) to an option type.
   ## It converts `nil` to `None`.
   ##
   ## See also:
@@ -483,6 +487,11 @@ when isMainModule:
       let tmp = option(intref)
       check(sizeof(tmp) == sizeof(ptr int))
       
+      var prc = proc (x: int): int = x + 1
+      check(option(prc).isSome)
+      prc = nil
+      check(option(prc).isNone)
+
     test "none[T]":
       check(none[int]().isNone)
       check(none(int) == none[int]())