support generic void return type for templates (#21934)

fixes #21920 (cherry picked from commit 2dcc719)
nim-lang · May 29, 2023 · ad0e497 · ad0e497
1 parent 23d4108
commit ad0e497
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Showing 2 changed files with 11 additions and 2 deletions.
diff --git a/compiler/sem.nim b/compiler/sem.nim
@@ -465,8 +465,11 @@ proc semAfterMacroCall(c: PContext, call, macroResult: PNode,
         retType = generateTypeInstance(c, paramTypes,
                                        macroResult.info, retType)
 
-      result = semExpr(c, result, flags, expectedType)
-      result = fitNode(c, retType, result, result.info)
+      if retType.kind == tyVoid:
+        result = semStmt(c, result, flags)
+      else:
+        result = semExpr(c, result, flags, expectedType)
+        result = fitNode(c, retType, result, result.info)
       #globalError(s.info, errInvalidParamKindX, typeToString(s.typ[0]))
   dec(c.config.evalTemplateCounter)
   discard c.friendModules.pop()

diff --git a/tests/template/template_issues.nim b/tests/template/template_issues.nim
@@ -296,3 +296,9 @@ block: # bug #12595
     discard {i: ""}
 
   test()
+
+block: # bug #21920
+  template t[T](): T =
+    discard
+
+  t[void]() # Error: expression has no type: discard