fix #7653

tests/cpp/tempty_generic_obj.nim

@@ -20,3 +20,19 @@ v.doSomething()
 
 var vf = initVector[float]()
 vf.doSomething() # Nim uses doSomething[int] here in C++
+
+# Alternative definition:
+# https://github.com/nim-lang/Nim/issues/7653
+
+type VectorAlt* {.importcpp: "std::vector", header: "<vector>", nodecl.} [T] = object
+proc mkVector*[T]: VectorAlt[T] {.importcpp: "std::vector<'*0>()", header: "<vector>", constructor, nodecl.}
+
+proc foo(): VectorAlt[cint] =
+  mkVector[cint]()
+
+proc bar(): VectorAlt[cstring] =
+  mkVector[cstring]()
+
+var x = foo()
+var y = bar()
+

tests/generics/t3977.nim

@@ -1,12 +1,14 @@
 discard """
-  output: '''42'''
+  output: "42\n42"
 """
 
 type
   Foo[N: static[int]] = object
 
 proc foo[N](x: Foo[N]) =
+  let n = N
   echo N
+  echo n
 
 var f1: Foo[42]
 f1.foo