xtd::any_object Class Reference

Inheritance diagram for xtd::any_object:

Definition

Represent a polymorphic wrapper capable of holding any type.

Header

#include <xtd/any_object>

Namespace

xtd

Library

xtd.core

Examples

The following code example illustrates the use of xtd::any_object class.

#include <xtd/xtd>
 
struct foo1 : public object, public icomparable<foo1>, public iequatable<foo1> {
  explicit foo1(int v) : value(v) {}
  int value = 0;
  
  string to_string() const noexcept override {return string::format("{}", value);}
  bool equals(const object& o) const noexcept override {return is<foo1>(o) && equals(static_cast<const foo1&>(o));}
  bool equals(const foo1& f) const noexcept override {return value == f.value;}
  int32 compare_to(const foo1& f) const noexcept override {return value < f.value ? -1 : value > f.value ? 1 : 0;}
};
 
struct foo2 {
  int value = 0;
  
  bool operator ==(const foo2& f) const noexcept {return value == f.value;}
  bool operator <(const foo2& f) const noexcept {return value < f.value;}
  bool operator >(const foo2& f) const noexcept {return value > f.value;}
};
 
template<>
std::string xtd::to_string(const foo2& value, const std::string& fmt, const std::locale& loc) {return xtd::int32_object {value.value}.to_string(fmt, loc);}
 
template<>
struct std::hash<foo2> {
  xtd::size operator()(const foo2& value) const noexcept {return xtd::hash_code::combine(value.value);}
};
 
auto main() -> int {
  auto a = any_object {};
  a = "one";
  console::write_line("a = {} => {} ({})", a, as<string>(a), typeof_(as<string>(a)));
  a = date_time {1971, 1, 5};
  console::write_line("a = {} => {} ({})", a, as<date_time>(a), typeof_(as<date_time>(a)));
  a = 42;
  console::write_line("a = {} => {} ({})", a, as<int32>(a), typeof_(as<int32>(a)));
  a = .42;
  console::write_line("a = {} => {} ({})", a, as<double>(a), typeof_(as<double>(a)));
  a = foo1 {42};
  console::write_line("a = {} => {} ({})", a, as<foo1>(a), typeof_(as<foo1>(a)));
  a = foo2 {42};
  console::write_line("a = {} => {} ({})", a, "NA", typeof_(as<foo2>(a)));
  a = day_of_week::wednesday;
  console::write_line("a = {} => {} ({})", a, as<day_of_week>(a), typeof_(as<day_of_week>(a)));
}
 
// This code produces the following output :
//
// a = one => one (xtd::string)
// a = Tue Jan  5 00:00:00 1971 => Tue Jan  5 00:00:00 1971 (xtd::date_time)
// a = 42 => 42 (int)
// a = 0.42 => 0.42 (double)
// a = 42 => 42 (foo1)
// a = foo2 => NA (foo2)
// a = wednesday => wednesday (xtd::day_of_week)

Remarks

TTo add a class, structure or any other type unknown to xtd, you need to implement the xtd::iequatable and xtd::icompoabale interfaces or overrride the == and < operetors.

Public Constructors
	any_object () noexcept=default
	Initializes a new instance of the xtd::any_object class.
template<class type_t>
	any_object (type_t &&value) noexcept
	Initializes a new instance of the xtd::any_object class with specified value.
template<class type_t>
	any_object (type_t &value) noexcept
	Initializes a new instance of the xtd::any_object class with specified value.
template<class type_t>
	any_object (const type_t &value) noexcept
	Initializes a new instance of the xtd::any_object class with specified value.

Public Properties
bool	has_value () const noexcept
	Gets a value indicating whether the current xtd::any_object object has a valid value of its underlying type.
const object &	value () const
	Gets the value of the current xtd::any_object object if it has been assigned a valid underlying value.

Public Methods
int32	compare_to (const any_object &other) const noexcept override
	Compares the current instance with another object of the same type.
bool	equals (const object &other) const noexcept override
	Determines whether the specified object is equal to the current object.
bool	equals (const any_object &other) const noexcept override
	Indicates whether the current object is equal to another object of the same type.
xtd::size	get_hash_code () const noexcept override
	Serves as a hash function for a particular type.
string	to_string () const noexcept override
	Returns a xtd::string that represents the current object.
void	reset () noexcept
	Reset the current object. Set the current object to null.

Public Operators
any_object &	operator= (const any_object &other) noexcept=default
	Copy assignment operator. Replaces the contents with a copy of the contents of other.
any_object &	operator= (any_object &&other) noexcept
	Move assignment operator. Replaces the contents with a copy of the contents of other.

Additional Inherited Members
	object ()=default
	Create a new instance of the ultimate base class object.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<class object_t>
xtd::unique_ptr_object< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
template<class object_a_t, class object_b_t>
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
template<class object_a_t, class object_b_t>
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Constructor & Destructor Documentation

any_object() [1/4]

xtd::any_object::any_object ( )

defaultnoexcept

Initializes a new instance of the xtd::any_object class.

any_object() [2/4]

template<class type_t>

xtd::any_object::any_object ( type_t && value )

inlinenoexcept

Initializes a new instance of the xtd::any_object class with specified value.

Parameters

value

The value to initialize the contained value with.

any_object() [3/4]

template<class type_t>

xtd::any_object::any_object ( type_t & value )

inlinenoexcept

Initializes a new instance of the xtd::any_object class with specified value.

Parameters

value

The value to initialize the contained value with.

any_object() [4/4]

template<class type_t>

xtd::any_object::any_object ( const type_t & value )

inlinenoexcept

Initializes a new instance of the xtd::any_object class with specified value.

Parameters

value

The value to initialize the contained value with.

Member Function Documentation

has_value()

bool xtd::any_object::has_value ( ) const

inlinenoexcept

Gets a value indicating whether the current xtd::any_object object has a valid value of its underlying type.

Returns

true if the current xtd::any_object object has a value; false if the current xtd::any_object object has no value.

Remarks

If the xtd::any_object::has_value property is true, the value of the current xtd::any_object object can be accessed with the xtd::any_object::value property. Otherwise, attempting to access its value throws an xtd::invalid_operation_exception exception.

value()

const object & xtd::any_object::value ( ) const

inline

Gets the value of the current xtd::any_object object if it has been assigned a valid underlying value.

Returns

The value of the current xtd::any_object object if the xtd::any_object::has_value property is true. An exception is thrown if the xtd::any_object::has_value property is false.

Exceptions

xtd::invalid_operation_exception

The xtd::any_object::has_value property is `false`.

compare_to()

int32 xtd::any_object::compare_to ( const any_object & other ) const

inlineoverridevirtualnoexcept

Compares the current instance with another object of the same type.

Parameters

obj	An object to compare with this instance.

Returns

A 32-bit signed integer that indicates the relative order of the objects being compared. The return value has these meanings:

Value	Condition
Less than zero	This instance is less than obj.
Zero	This instance is equal to obj.
Greater than zero	This instance is greater than obj.

Implements xtd::icomparable< any_object >.

equals() [1/2]

bool xtd::any_object::equals ( const object & other ) const

inlineoverridevirtualnoexcept

Determines whether the specified object is equal to the current object.

Parameters

obj	The object to compare with the current object.

Returns

true if the specified object is equal to the current object. otherwise, false.

Reimplemented from xtd::object.

equals() [2/2]

bool xtd::any_object::equals ( const any_object & other ) const

inlineoverridevirtualnoexcept

Indicates whether the current object is equal to another object of the same type.

Parameters

obj	An object to compare with this object.

Returns

true if the current object is equal to the other parameter; otherwise, false.

Implements xtd::iequatable< any_object >.

get_hash_code()

xtd::size xtd::any_object::get_hash_code ( ) const

inlineoverridevirtualnoexcept

Serves as a hash function for a particular type.

Returns

A hash code for the current object.

Reimplemented from xtd::object.

to_string()

string xtd::any_object::to_string ( ) const

inlineoverridevirtualnoexcept

Returns a xtd::string that represents the current object.

Returns

A string that represents the current object.

Reimplemented from xtd::object.

Examples

generic_ienumerable2.cpp, and generic_ienumerator.cpp.

reset()

void xtd::any_object::reset ( )

inlinenoexcept

Reset the current object. Set the current object to null.

Remarks

If xtd::any_object::has_values is true, destroys the contained object; otherwise does nothing.

operator=() [1/2]

any_object & xtd::any_object::operator= ( const any_object & other )

defaultnoexcept

Copy assignment operator. Replaces the contents with a copy of the contents of other.

Parameters

other

Another polymorphic wrapper.

Returns

This current instance.

operator=() [2/2]

any_object & xtd::any_object::operator= ( any_object && other )

inlinenoexcept

Move assignment operator. Replaces the contents with a copy of the contents of other.

Parameters

other

Another polymorphic wrapper.

Returns

This current instance.

---

The documentation for this class was generated from the following file:

• xtd.core/include/xtd/any_object.hpp