ClassTag
Related Docs:
object ClassTag
| package reflect
Test two objects for inequality.
Test two objects for inequality.
true if !(this == that), false otherwise.
Equivalent to x.hashCode except for boxed numeric types and null.
Equivalent to x.hashCode except for boxed numeric types and null.
For numerics, it returns a hash value which is consistent
with value equality: if two value type instances compare
as true, then ## will produce the same hash value for each
of them.
For null returns a hashcode where null.hashCode throws a
NullPointerException.
a hash value consistent with ==
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
the object to compare against this object for equality.
true if the receiver object is equivalent to the argument; false otherwise.
Cast the receiver object to be of type T0.
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at
runtime, while the expression List(1).asInstanceOf[List[String]] will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException if the receiver object is not an instance of the erasure of type T0.
A method that should be called from every well-designed equals method that is open to be overridden in a subclass.
A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.
true if this instance can possibly equal that, otherwise false
Create a copy of the receiver object.
Tests whether the argument (arg0) is a reference to the receiver object (this).
Tests whether the argument (arg0) is a reference to the receiver object (this).
The eq method implements an equivalence relation on
non-null instances of AnyRef, and has three additional properties:
x and y of type AnyRef, multiple invocations of
x.eq(y) consistently returns true or consistently returns false.x of type AnyRef, x.eq(null) and null.eq(x) returns false.null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they
should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
true if the argument is a reference to the receiver object; false otherwise.
The universal equality method defined in AnyRef.
Called by the garbage collector on the receiver object when there are no more references to the object.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as
well as the interaction between finalize and non-local returns
and exceptions, are all platform dependent.
Returns string formatted according to given format string.
Returns string formatted according to given format string.
Format strings are as for String.format
(@see java.lang.String.format).
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
not specified by SLS as a member of AnyRef
The hashCode method for reference types.
Test whether the dynamic type of the receiver object is T0.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String] will return false, while the
expression List(1).isInstanceOf[List[String]] will return true.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true if the receiver object is an instance of erasure of type T0; false otherwise.
Equivalent to !(this eq that).
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
Produces a new array with element type T and length len
Produces a new array with element type T and length len
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Creates a String representation of this object.
A ClassTag[T] can serve as an extractor that matches only objects of type T.
A ClassTag[T] can serve as an extractor that matches only objects of type T.
The compiler tries to turn unchecked type tests in pattern matches into checked ones
by wrapping a (_: T) type pattern as ct(_: T), where ct is the ClassTag[T] instance.
Type tests necessary before calling other extractors are treated similarly.
SomeExtractor(...) is turned into ct(SomeExtractor(...)) if T in SomeExtractor.unapply(x: T)
is uncheckable, but we have an instance of ClassTag[T].
Produces a ClassTag that knows how to instantiate an Array[Array[T]]
Tests whether the type represented by this manifest is a subtype
of the type represented by that manifest, subject to the limitations
described in the header.
Tests whether the type represented by this manifest is a subtype
of the type represented by that manifest, subject to the limitations
described in the header.
(Since version 2.10.0) Use scala.reflect.runtime.universe.TypeTag for subtype checking instead
Tests whether the type represented by this manifest is a supertype
of the type represented by that manifest, subject to the limitations
described in the header.
Tests whether the type represented by this manifest is a supertype
of the type represented by that manifest, subject to the limitations
described in the header.
(Since version 2.10.0) Use scala.reflect.runtime.universe.TypeTag for subtype checking instead
(Since version 2.10.0) Use wrap instead
(Since version 2.10.0) Use runtimeClass instead
(Since version 2.10.0) Use wrap.newArray instead
(Since version 2.10.0) Use wrap.wrap.newArray instead
(Since version 2.10.0) Use wrap.wrap.wrap.newArray instead
(Since version 2.10.0) Use wrap.wrap.wrap.wrap.newArray instead
(Since version 2.10.0) Use ArrayBuilder.make(this) instead
(Since version 2.10.0) Create WrappedArray directly instead
(Since version 2.10.0) Use scala.reflect.runtime.universe.TypeTag to capture type structure instead
A
ClassTag[T]stores the erased class of a given typeT, accessible via theruntimeClassfield. This is particularly useful for instantiatingArrays whose element types are unknown at compile time.ClassTags are a weaker special case of scala.reflect.api.TypeTags#TypeTags, in that they wrap only the runtime class of a given type, whereas aTypeTagcontains all static type information. That is,ClassTags are constructed from knowing only the top-level class of a type, without necessarily knowing all of its argument types. This runtime information is enough for runtimeArraycreation.For example:
See scala.reflect.api.TypeTags for more examples, or the Reflection Guide: TypeTags for more details.