fixes #3706

compiler/ccgtypes.nim

@@ -150,6 +150,9 @@ proc mapType(typ: PType): TCTypeKind =
   of tyCString: result = ctCString
   of tyInt..tyUInt64:
     result = TCTypeKind(ord(typ.kind) - ord(tyInt) + ord(ctInt))
+  of tyStatic:
+    if typ.n != nil: result = mapType(lastSon typ)
+    else: internalError("mapType")
   else: internalError("mapType")
 
 proc mapReturnType(typ: PType): TCTypeKind =
@@ -256,6 +259,11 @@ proc getSimpleTypeDesc(m: BModule, typ: PType): Rope =
   of tyInt..tyUInt64:
     result = typeNameOrLiteral(typ, NumericalTypeToStr[typ.kind])
   of tyDistinct, tyRange, tyOrdinal: result = getSimpleTypeDesc(m, typ.sons[0])
+  of tyStatic:
+    if typ.n != nil: result = getSimpleTypeDesc(m, lastSon typ)
+    else: internalError("tyStatic for getSimpleTypeDesc")
+  of tyGenericInst:
+    result = getSimpleTypeDesc(m, lastSon typ)
   else: result = nil
 
 proc pushType(m: BModule, typ: PType) =
@@ -1025,6 +1033,9 @@ proc genTypeInfo(m: BModule, t: PType): Rope =
   of tyEmpty, tyVoid: result = rope"0"
   of tyPointer, tyBool, tyChar, tyCString, tyString, tyInt..tyUInt64, tyVar:
     genTypeInfoAuxBase(m, t, t, result, rope"0")
+  of tyStatic:
+    if t.n != nil: result = genTypeInfo(m, lastSon t)
+    else: internalError("genTypeInfo(" & $t.kind & ')')
   of tyProc:
     if t.callConv != ccClosure:
       genTypeInfoAuxBase(m, t, t, result, rope"0")

compiler/jsgen.nim

@@ -164,8 +164,11 @@ proc mapType(typ: PType): TJSTypeKind =
   of tyNil: result = etyNull
   of tyGenericInst, tyGenericParam, tyGenericBody, tyGenericInvocation,
      tyNone, tyFromExpr, tyForward, tyEmpty, tyFieldAccessor,
-     tyExpr, tyStmt, tyStatic, tyTypeDesc, tyTypeClasses, tyVoid:
+     tyExpr, tyStmt, tyTypeDesc, tyTypeClasses, tyVoid:
     result = etyNone
+  of tyStatic:
+    if t.n != nil: result = mapType(lastSon t)
+    else: result = etyNone
   of tyProc: result = etyProc
   of tyCString: result = etyString
 
@@ -1427,6 +1430,12 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
       result = putToSeq("null", indirect)
   of tySequence, tyString, tyCString, tyPointer, tyProc:
     result = putToSeq("null", indirect)
+  of tyStatic:
+    if t.n != nil:
+      result = createVar(p, lastSon t, indirect)
+    else:
+      internalError("createVar: " & $t.kind)
+      result = nil
   else:
     internalError("createVar: " & $t.kind)
     result = nil

compiler/jstypes.nim

@@ -165,4 +165,7 @@ proc genTypeInfo(p: PProc, typ: PType): Rope =
   of tyEnum: genEnumInfo(p, t, result)
   of tyObject: genObjectInfo(p, t, result)
   of tyTuple: genTupleInfo(p, t, result)
+  of tyStatic:
+    if t.n != nil: result = genTypeInfo(p, lastSon t)
+    else: internalError("genTypeInfo(" & $t.kind & ')')
   else: internalError("genTypeInfo(" & $t.kind & ')')

compiler/types.nim

@@ -1317,6 +1317,9 @@ proc computeSizeAux(typ: PType, a: var BiggestInt): BiggestInt =
   of tyTypeDesc:
     result = computeSizeAux(typ.base, a)
   of tyForward: return szIllegalRecursion
+  of tyStatic:
+    if typ.n != nil: result = computeSizeAux(lastSon(typ), a)
+    else: result = szUnknownSize
   else:
     #internalError("computeSizeAux()")
     result = szUnknownSize

tests/metatype/tmodulo.nim

@@ -0,0 +1,20 @@
+discard """
+  output: '''1 mod 7'''
+"""
+
+# bug #3706
+
+type Modulo[M: static[int]] = distinct int
+
+proc modulo(a: int, M: static[int]): Modulo[M] = Modulo[M](a %% M)
+
+proc `+`[M: static[int]](a, b: Modulo[M]): Modulo[M] = (a.int + b.int).modulo(M)
+
+proc `$`*[M: static[int]](a: Modulo[M]): string = $(a.int) & " mod " & $(M)
+
+when isMainModule:
+  let
+    a = 3.modulo(7)
+    b = 5.modulo(7)
+  echo a + b
+