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Type support (basic types, RTTI, type traits)

From cppreference.com
< cpp
 
 
 
Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
numeric_limits
C numeric limits interface
Runtime type information
Type traits
Primary type categories
is_void(C++11)
is_array(C++11)
is_pointer(C++11)
is_enum(C++11)
is_union(C++11)
is_class(C++11)
is_function(C++11)
is_object(C++11)
is_scalar(C++11)
is_compound(C++11)
is_integral(C++11)
is_floating_point(C++11)
is_fundamental(C++11)
is_arithmetic(C++11)
is_reference(C++11)
is_lvalue_reference(C++11)
is_rvalue_reference(C++11)
is_member_pointer(C++11)
is_member_object_pointer(C++11)
is_member_function_pointer(C++11)
Type properties
is_const(C++11)
is_volatile(C++11)
is_pod(C++11)
is_empty(C++11)
is_polymorphic(C++11)
is_abstract(C++11)
Supported operations
is_constructible
is_trivially_constructible
is_nothrow_constructible
(C++11)
(C++11)
(C++11)
is_default_constructible
is_trivially_default_constructible
is_nothrow_default_constructible
(C++11)
(C++11)
(C++11)
is_copy_constructible
is_trivially_copy_constructible
is_nothrow_copy_constructible
(C++11)
(C++11)
(C++11)
is_move_constructible
is_trivially_move_constructible
is_nothrow_move_constructible
(C++11)
(C++11)
(C++11)
is_assignable
is_trivially_assignable
is_nothrow_assignable
(C++11)
(C++11)
(C++11)
is_copy_assignable
is_trivially_copy_assignable
is_nothrow_copy_assignable
(C++11)
(C++11)
(C++11)
is_move_assignable
is_trivially_move_assignable
is_nothrow_move_assignable
(C++11)
(C++11)
(C++11)
is_destructible
is_trivially_destructible
is_nothrow_destructible
(C++11)
(C++11)
(C++11)
has_virtual_destructor(C++11)
Relationships and property queries
is_same(C++11)
is_base_of(C++11)
is_convertible(C++11)
alignment_of(C++11)
rank(C++11)
extent(C++11)
Type modifications
remove_cv
remove_const
remove_volatile
(C++11)
(C++11)
(C++11)
add_cv
add_const
add_volatile
(C++11)
(C++11)
(C++11)
make_signed(C++11)
make_unsigned(C++11)
Type transformations
aligned_storage(C++11)
aligned_union(C++11)
decay(C++11)
enable_if(C++11)
conditional(C++11)
common_type(C++11)
underlying_type(C++11)
result_of(C++11)
Type trait constants
integral_constant(C++11)
 

Contents

[edit] Basic types

[edit] Fundamental types defined by the language

[edit] Additional basic types and macros

Defined in header <cstddef>
unsigned integer type returned by the sizeof operator
(typedef) [edit]
signed integer type returned when subtracting two pointers
(typedef) [edit]
(C++11)
the type of the null pointer literal nullptr
(typedef) [edit]
implementation-defined null pointer constant
(macro constant) [edit]
POD type with alignment requirement as great as any other scalar type
(typedef) [edit]
byte offset from the beginning of a standard-layout type to specified member
(function macro) [edit]
Defined in header <cstdbool>
__bool_true_false_are_defined
(C++11)
C compatibility macro constant, expands to integer constant 1
(macro constant)
Defined in header <cstdalign>
__alignas_is_defined
(C++11)
C compatibility macro constant, expands to integer constant 1
(macro constant)

[edit] Fixed width integer types (since C++11)

[edit] numeric_limits

Defined in header <limits>
provides an interface to query properties of all fundamental numeric types.
(class template) [edit]

[edit] C numeric limits interface

[edit] Runtime type identification

contains some type's information, generated by the implementation.
This is the class, returned by the typeid operator
(class) [edit]
wrapper around a type_info object, that can be used as index in associative and unordered associative containers
(class) [edit]
exception that is thrown if an argument in a typeid expression is null
(class) [edit]
exception that is thrown by an invalid dynamic_cast expression, i.e. a cast of reference type fails
(class) [edit]

[edit] Type traits (since C++11)

Type traits defines an compile-time template-based interface to query or modify the properties of types.

[edit] Type properties

Defined in header <type_traits>
Primary type categories
(C++11)
checks if a type is void
(class template) [edit]
checks if a type is integral type
(class template) [edit]
checks if a type is floating-point type
(class template) [edit]
(C++11)
checks if a type is an array type
(class template) [edit]
(C++11)
checks if a type is an enumeration type
(class template) [edit]
(C++11)
checks if a type is an union type
(class template) [edit]
(C++11)
checks if a type is a class type (but not union type)
(class template) [edit]
checks if a type is a function type
(class template) [edit]
checks if a type is a pointer type
(class template) [edit]
checks if a type is lvalue reference
(class template) [edit]
checks if a type is rvalue reference
(class template) [edit]
checks if a type is a pointer to a non-static member object
(class template) [edit]
checks if a type is a pointer to a non-static member function
(class template) [edit]
Composite type categories
checks if a type is fundamental type
(class template) [edit]
checks if a type is arithmetic type
(class template) [edit]
(C++11)
checks if a type is scalar type
(class template) [edit]
(C++11)
checks if a type is object type
(class template) [edit]
checks if a type is compound type
(class template) [edit]
checks if a type is either lvalue reference or rvalue reference
(class template) [edit]
checks if a type is a pointer to a non-static member function or object
(class template) [edit]
Type properties
(C++11)
checks if a type is const-qualified
(class template) [edit]
checks if a type is volatile-qualified
(class template) [edit]
checks if a type is trivial
(class template) [edit]
checks if a type is trivially copyable
(class template) [edit]
checks if a type is standard-layout type
(class template) [edit]
(C++11)
checks if a type is plain-old data (POD) type
(class template) [edit]
checks if a type is literal type
(class template) [edit]
(C++11)
checks if a type is class (but not union) type and has no data
(class template) [edit]
checks if a type is polymorphic class type
(class template) [edit]
checks if a type is abstract class type
(class template) [edit]
(C++11)
checks if a type is signed arithmetic type
(class template) [edit]
checks if a type is unsigned arithmetic type
(class template) [edit]
Supported operations
checks if a type has a constructor for specific arguments
(class template) [edit]
checks if a type has a default constructor
(class template) [edit]
checks if a type has a copy constructor
(class template) [edit]
checks if a type has a move constructor
(class template) [edit]
checks if a type has a assignment operator for a specific argument
(class template) [edit]
checks if a type has a copy assignment operator
(class template) [edit]
checks if a type has a move assignment operator
(class template) [edit]
checks if a type has a non-deleted destructor
(class template) [edit]
checks if a type has a virtual destructor
(class template) [edit]
Property queries
obtains the type's alignment requirements
(class template) [edit]
(C++11)
obtains the number of dimensions of an array type
(class template) [edit]
(C++11)
obtains the size of an array type along a specified dimension
(class template) [edit]
Type relationships
(C++11)
checks if two types are the same
(class template) [edit]
checks if a type is derived from the other type
(class template) [edit]
checks if a type can be converted to the other type
(class template) [edit]

[edit] Type modifications

Type modification templates create new type definitions by applying modifications on a template parameter. The resulting type can then be accessed through type member typedef.

Defined in header <type_traits>
Const-volatility specifiers
removes const or/and volatile specifiers from the given type
(class template) [edit]
(C++11)
(C++11)
(C++11)
adds const or/and volatile specifiers to the given type
(class template) [edit]
References
removes reference from the given type
(class template) [edit]
adds lvalue or rvalue reference to the given types
(class template) [edit]
Pointers
removes pointer from the given type
(class template) [edit]
adds pointer to the given type
(class template) [edit]
Sign modifiers
makes the given integral type signed
(class template) [edit]
makes the given integral type unsigned
(class template) [edit]
Arrays
removes one extent from the given array type
(class template) [edit]
removes all extents from the given array type
(class template) [edit]

[edit] Miscellaneous transformations

Defined in header <type_traits>
defines the type suitable for use as uninitialized storage for types of given size
(class template) [edit]
defines the type suitable for use as uninitialized storage for all given types
(class template) [edit]
(C++11)
applies type transformations as when passing a function argument by value
(class template) [edit]
(C++11)
hides a function overload or template specialization based on compile-time boolean
(class template) [edit]
chooses one type or another based on compile-type boolean
(class template) [edit]
deduces the result type of a mixed-mode arithmetic expression
(class template) [edit]
obtains the underlying integer type for a given enumeration type
(class template) [edit]
(C++11)
deduces the return type of a function call expresion
(class template) [edit]

[edit] Helper classes

Defined in header <type_traits>
compile-time constant of specified type with specified value
(class template) [edit]

Two specializations of std::integral_constant for the type bool are provided:

Defined in header <type_traits>
Type Definition
true_type std::integral_constant<bool, true>
false_type std::integral_constant<bool, false>