fixes #10038; deprecate generic methods, they are unreliable

Author: Araq

changelog.md

@@ -33,6 +33,7 @@
   tree from the symbol declaration instead of just the initializer portion.
 
 - To use multi-methods, explicit `--multimethods:on` is now needed.
+- Generic methods are now deprecated; they never worked well.
 
 - Compile time checks for integer and float conversions are now stricter.
   For example, `const x = uint32(-1)` now gives a compile time error instead
@@ -45,7 +46,8 @@
 - A bug allowed `macro foo(): int = 123` to compile even though a
   macros has to return a `NimNode`. This has been fixed.
 
-- With the exception of `uint` and `uint64`, conversion to unsigned types are now range checked during runtime.
+- With the exception of `uint` and `uint64`, conversion to unsigned types
+  are now range checked during runtime.
 
 #### Breaking changes in the standard library
 

compiler/semstmts.nim

@@ -1712,8 +1712,9 @@ proc semMethodPrototype(c: PContext; s: PSym; n: PNode) =
         if x.kind == tyObject and t.len-1 == n.sons[genericParamsPos].len:
           foundObj = true
           x.methods.add((col,s))
-    if not foundObj:
-      message(c.config, n.info, warnDeprecated, "generic method not attachable to object type is deprecated")
+    message(c.config, n.info, warnDeprecated, "generic methods are deprecated")
+    #if not foundObj:
+    #  message(c.config, n.info, warnDeprecated, "generic method not attachable to object type is deprecated")
   else:
     # why check for the body? bug #2400 has none. Checking for sfForward makes
     # no sense either.

doc/manual.rst

@@ -3526,6 +3526,8 @@ the effects that a call to ``m`` might cause.
 
 **Note**: Compile-time execution is not (yet) supported for methods.
 
+**Note**: Starting from Nim 0.20, generic methods are deprecated.
+
 
 Inhibit dynamic method resolution via procCall
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