closes #10219; adds a test case (#23370)

closes #10219

tests/cpp/torc.nim

@@ -39,3 +39,23 @@ proc asVector*[T](t: T): EnumVector[T] =
 # N_NIMCALL(std::vector<> , asvector_106028_3197418230)(SomeEnum t0)
 
 discard asVector(SomeEnum.A)
+
+
+block: # bug #10219
+  type
+    Vector[T]  {.importcpp: "std::vector", header: "vector".} = object
+
+  proc initVector[T](n: csize_t): Vector[T] 
+      {.importcpp: "std::vector<'*0>(@)", header: "vector".}
+
+  proc unsafeIndex[T](this: var Vector[T], i: csize_t): var T 
+      {.importcpp: "#[#]", header: "vector".}
+
+  proc `[]`[T](this: var Vector[T], i: Natural): var T {.inline, noinit.} =
+    when compileOption("boundChecks"):
+        # this.checkIndex i
+        discard
+    result = this.unsafeIndex(csize_t(i))
+
+  var v1 = initVector[int](10)
+  doAssert v1[0] == 0