diff --git a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
index 511ba12a3..7d8ac6040 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
@@ -741,7 +741,7 @@ internal class AstChecker(private val program: Program,
 
     override fun visit(array: ArrayLiteralValue) {
         if(array.type.isKnown) {
-            if (!compilerOptions.floats && array.type.getOr(DataType.UNDEFINED) in setOf(DataType.FLOAT, DataType.ARRAY_F)) {
+            if (!compilerOptions.floats && array.type.oneOf(DataType.FLOAT, DataType.ARRAY_F)) {
                 errors.err("floating point used, but that is not enabled via options", array.position)
             }
             val arrayspec = ArrayIndex.forArray(array)
@@ -1157,7 +1157,7 @@ internal class AstChecker(private val program: Program,
                 when {
                     constvalue == null -> errors.err("choice value must be a constant", whenChoice.position)
                     constvalue.type !in IntegerDatatypes -> errors.err("choice value must be a byte or word", whenChoice.position)
-                    constvalue.type != conditionType.getOr(DataType.UNDEFINED) -> errors.err("choice value datatype differs from condition value", whenChoice.position)
+                    !conditionType.istype(constvalue.type) -> errors.err("choice value datatype differs from condition value", whenChoice.position)
                 }
             }
         } else {
diff --git a/compilerAst/src/prog8/ast/expressions/InferredTypes.kt b/compilerAst/src/prog8/ast/expressions/InferredTypes.kt
index 857c273f6..55dd6eea6 100644
--- a/compilerAst/src/prog8/ast/expressions/InferredTypes.kt
+++ b/compilerAst/src/prog8/ast/expressions/InferredTypes.kt
@@ -15,6 +15,8 @@ object InferredTypes {
         fun getOrElse(transform: (InferredType) -> DataType): DataType =
             if(isUnknown || isVoid) transform(this) else datatype!!
         infix fun istype(type: DataType): Boolean = if(isUnknown || isVoid) false else this.datatype==type
+        infix fun isnot(type: DataType): Boolean = if(isUnknown || isVoid) true else this.datatype!=type
+        fun oneOf(vararg types: DataType) = if(isUnknown || isVoid) false else this.datatype in types
 
         companion object {
             fun unknown() = InferredType(isUnknown = true, isVoid = false, datatype = null)
diff --git a/docs/source/todo.rst b/docs/source/todo.rst
index 04237514a..af51107a8 100644
--- a/docs/source/todo.rst
+++ b/docs/source/todo.rst
@@ -3,7 +3,9 @@ TODO
 
 For next compiler release
 ^^^^^^^^^^^^^^^^^^^^^^^^^
-...
+replace uses of inferredType.istype(..) by infix form
+replace checks against multiple types with .oneOf(...)
+replace certain uses of inferredType.getOr(UNKNOWN) by i.getOrElse({ errorhandler })
 
 
 Blocked by Commander-x16 v39 release