struct factory.anyany structs accept any value as valid.any struct will loosen the type to any, and you might want to use unknown instead.arrayarray structs accept a list of values of a specific type.bigintbigint structs validate that a value is a bigint.booleanboolean structs accept the boolean values true and false.datedate structs accept JavaScript Date instances.date structs do not accept invalid Date objects, even though they are technically an instance of a Date. This meshes with the 99% use case where invalid dates create inconsistencies.enumsenums structs validate that a value is one of a specific set of literals values.funcfunc structs validate that a value is a function.instanceinstance structs validate that a value is an instance of a particular class, using JavaScript's built-in instanceof operator.integerinteger structs validate that a value is an integer.intersectionintersection structs validate that a value matches all of many structs. It takes existing struct objects as arguments.literalliteral structs enforce that a value matches an exact value using the === operator.mapmap structs validate that a value is a Map object with specific types for its keys and values.map it will traverse all the properties to ensure they are valid! If you don't care about validating the properties of the map, you can write map() instead.nevernever structs will fail validation for every value.numbernumber structs validate that a value is a number.nullablenullable structs validate that a value matches a specific struct, or that it is null.objectobject structs validate that a value is an object and that each of its properties match a specific type as well.optionaloptional structs validate that a value matches a specific struct, or that it is undefined.recordrecord structs validate an object with specific types for its keys and values. But, unlike object structs, they do not enforce a specific set of keys.regexpregexp structs validate that a value is a RegExp object.pattern refinement.setset structs validate that a value is a Set instance with elements of a specific type.set it will traverse all the children to ensure they are valid! If you don't care about validating the elements of the set, you can write set() instead.stringstring structs validate that a value is a string.tupletuple structs validate that a value is an array of a specific length with values each of a specific type.typetype structs validate that a value has a set of properties on it, but it does not assert anything about unspecified properties. This allows you to assert that a particular set of functionality exists without a strict equality check for properties.mask() is used with a value of type, its unknown properties are not removed. I.e. consider type as a signal to the core that the object may have arbitrary properties in addition to the known ones, in both masked and non-masked validation.unionunion structs validate that a value matches at least one of many types.unknownunknown structs accept unknown value as valid without loosening its type to any.true/false or an array of StructFailure objects, in case you want to build more helpful error messages.unknown by default. You can pass a more specific type for Typescript: