macros: distinct literals (#235)

stew/shims/macros.nim

@@ -1,5 +1,5 @@
 import
-  std/[macros, tables, hashes]
+  std/[hashes, macros, tables, typetraits]
 
 export
   macros
@@ -395,6 +395,11 @@ proc newLitFixed*(arg: tuple): NimNode {.compileTime.} =
   for a,b in arg.fieldPairs:
     result.add nnkExprColonExpr.newTree(newIdentNode(a), newLitFixed(b))
 
+proc newLitFixed*(arg: distinct): NimNode {.compileTime.} =
+  result = newLitFixed distinctBase(arg)
+  var typ = getTypeInst(typeof(arg))[1]
+  result = newCall(typ,result)
+
 iterator typedParams*(n: NimNode, skip = 0): (NimNode, NimNode) =
   let params = n[3]
   for i in (1 + skip) ..< params.len: