<type_traits>

Article
11/16/2012

Defines templates that provide compile-time constants that give information about the properties of their type arguments.

#include <type_traits>

Remarks

A type predicate is a template that takes one or two type arguments. When a type predicate holds true, it is publicly derived, directly or indirectly, from true_type Typedef. When a type predicate holds false, it is publicly derived, directly or indirectly, from false_type Typedef.

A type modifier is a template that takes one or more template arguments and has one member, as follows:

typedef modified-type type;

A type query is a template that takes one or more template arguments. A type query is publicly derived, directly or indirectly, from integral_constant<std::size_t, value>. It holds the value that is passed as the argument value.

Declarations

Class	Description
add_const Class	Makes const type from type.
add_cv Class	Makes const/volatile type from type.
add_pointer Class	Makes pointer to type from type.
add_reference Class	Makes reference to type from type.
add_volatile Class	Makes volatile type from type.
aligned_storage Class	Makes suitably aligned type.
alignment_of Class	Gets alignment of type.
extent Class	Gets an array dimension.
has_nothrow_assign Class	Tests whether the type does not throw on assign.
has_nothrow_constructor Class	Tests whether the type does not throw on default construction.
has_nothrow_copy Class	Tests whether the type does not throw on copy construction.
has_trivial_assign Class	Tests whether the type has trivial assign.
has_trivial_constructor Class	Tests whether the type has trivial default constructor.
has_trivial_copy Class	Tests whether the type has trivial copy constructor.
has_trivial_destructor Class	Tests whether the type has trivial destructor.
has_virtual_destructor Class	Tests whether the type has virtual destructor.
is_abstract Class	Tests whether the type is abstract class.
is_arithmetic Class	Tests whether the type is arithmetic.
is_array Class	Tests whether the type is array.
is_base_of Class	Tests whether one type is the base of another.
is_class Class	Tests whether the type is a class.
is_compound Class	Tests whether the type is not scalar.
is_const Class	Tests whether the type is const.
is_convertible Class	Tests whether one type is convertible to another.
is_empty Class	Tests whether the type is an empty class.
is_enum Class	Tests whether the type is an enumeration.
is_floating_point Class	Tests whether the type is floating-point.
is_function Class	Tests whether the type is a function type.
is_fundamental Class	Tests whether the type is void or arithmetic.
is_integral Class	Tests whether the type is integral.
is_member_function_pointer Class	Tests whether the type is a pointer to a member function.
is_member_object_pointer Class	Tests whether the type is a pointer to a member object.
is_member_pointer Class	Tests whether the type is a pointer to a member.
is_object Class	Tests whether the type is an object type.
is_pod Class	Tests whether the type is a POD.
is_pointer Class	Tests whether the type is a pointer.
is_polymorphic Class	Tests whether the type has a virtual function.
is_reference Class	Tests whether the type is a reference.
is_same Class	Tests whether two types are the same.
is_scalar Class	Tests whether the type is scalar.
is_signed Class	Tests whether the type is a signed integer.
is_union Class	Tests whether the type is a union.
is_unsigned Class	Tests whether the type is an unsigned integer.
is_void Class	Tests whether the type is void.
is_volatile Class	Tests whether the type is volatile.
rank Class	Gets the number of array dimensions.
remove_all_extents Class	Makes non-array type from array type.
remove_const Class	Makes non-const type from type.
remove_cv Class	Makes non-const/volatile type from type.
remove_extent Class	Makes element type from array type.
remove_pointer Class	Makes type from a pointer to type.
remove_reference Class	Makes non-reference type from type.
remove_volatile Class	Makes non-volatile type from type.
integral_constant Class	Makes integral constant from type and value.

Type Definitions

Type	Description
false_type Typedef	Holds integral constant with false value.
true_type Typedef	Holds integral constant with true value.

<type_traits>

Remarks

Declarations

Type Definitions

See Also

Reference

Additional resources