xtd::box< type_t > Class Template Reference

Inheritance diagram for xtd::box< type_t >:

Definition

template<typename type_t>
class xtd::box< type_t >

Represents a boxed object.

class box : public xtd::icomparable<box<type_t>>, public xtd::iequatable<box<type_t>>, public xtd::object

Inheritance

xtd::object → xtd::box <type_t>

Implements

xtd::icomparable <>, xtd::iequatable <>

Header

#include <xtd/box>

Namespace

xtd

Library

xtd.core

Remarks

You can use xtd::box to represent a class or structure that does not inherit from xtd::object. Typically used for integral types.

Use xtd::boxing to box an object.

Use xtd::unboxing to unbox an object.

The boxed object must implement operator == and operator < because a xtd::box implement xtd::icomparable and xtd::iequatable interfaces.

For more information about types, see Native types, boxing and unboxing.

Examples

The following example shows how to create and use xtd::box<bool>.

auto stringer = [](const object& value) {return value.to_string();};
bool unboxed_object = true;
box<bool> boxed_object = unboxed_bool;
auto result = stringer(boxed_object);
console::write_line("result = {}", result); // Display: result = true;

Examples

generic_icollection.cpp, generic_ienumerable2.cpp, generic_ienumerator.cpp, and generic_ilist.cpp.

Public Types
using	underlying_type = type_t

Public Constructors
	box ()=default
	Initialize a new xtd::box object.
	box (const type_t &value)
	Initialize a new xtd::box object with specified value.
template<typename ... args_t>
	box (args_t &&...args)
	Initialize a new xtd::box object with specified value.

Public Properties
const type_t &	value () const noexcept
	Gets the underlying value.
type_t &	value () noexcept
	Gets the underlying value.
box &	value (const type_t &value)
	Sets de underlying value.

Opertors
	operator type_t () const noexcept

Public Methods
int32	compare_to (const box &value) const noexcept override
	Compares the current instance with another object of the same type.
bool	equals (const object &obj) const noexcept override
	Determines whether the specified object is equal to the current object.
bool	equals (const box &value) const noexcept override
	Indicates whether the current object is equal to another object of the same type.
xtd::string	to_string () const noexcept override
	Returns a xtd::string that represents the current object.
xtd::string	to_string (const xtd::string &format) const
	Converts the value of this instance to its equivalent string representation, using the specified format.
xtd::string	to_string (const xtd::string &format, const std::locale &loc) const override
	Converts the value of this instance to its equivalent string representation, using the specified format, and locale.

Public Static Methods
static type_t	parse (const xtd::string &value)
	Converts the string to its type_t equivalent.
static bool	try_parse (const xtd::string &value, type_t &result) noexcept
	Converts the string to its type_t equivalent. A return value indicates whether the conversion succeeded or failed.

Additional Inherited Members
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<typename object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
Public Member Functions inherited from xtd::icomparable< box< type_t > >
Public Member Functions inherited from xtd::iequatable< box< type_t > >
Public Member Functions inherited from xtd::iformatable
Static Public Member Functions inherited from xtd::object
template<typename object_a_t , typename 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<typename object_a_t , typename 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

box() [1/3]

template<typename type_t >

xtd::box< type_t >::box ( )

default

Initialize a new xtd::box object.

box() [2/3]

template<typename type_t >

xtd::box< type_t >::box ( const type_t &  value )

inline

Initialize a new xtd::box object with specified value.

Parameters

value

Value used to initialize object.

box() [3/3]

template<typename type_t >

template<typename ... args_t>

xtd::box< type_t >::box ( args_t &&...  args )

inline

Initialize a new xtd::box object with specified value.

Parameters

...args_t

Params used to initialize object.

Member Function Documentation

value() [1/3]

template<typename type_t >

const type_t & xtd::box< type_t >::value ( ) const

inlinenoexcept

Gets the underlying value.

Returns

Return the underlying value.

value() [2/3]

template<typename type_t >

type_t & xtd::box< type_t >::value ( )

inlinenoexcept

Gets the underlying value.

Returns

Return the underlying value.

value() [3/3]

template<typename type_t >

box & xtd::box< type_t >::value ( const type_t &  value )

inline

Sets de underlying value.

Parameters

value

The value to set to the underlying value.

compare_to()

template<typename type_t >

int32 xtd::box< type_t >::compare_to ( const box< type_t > &  obj ) 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< box< type_t > >.

equals() [1/2]

template<typename type_t >

bool xtd::box< type_t >::equals ( const object &  obj ) 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.

Examples

The following code example compares the current instance with another object.

#include <xtd/console>
 
using namespace xtd;
 
auto main() -> int {
  auto object1 = new_ptr<object>();
  auto object2 = new_ptr<object>();
  
  auto object3 = object2;
  console::write_line(object1->equals(*object3));
  console::write_line(*object1 == *object3);
  object3 = object1;
  console::write_line(object1->equals(*object3));
  console::write_line(*object1 == *object3);
}
 
// This code produces the following output :
//
// false
// false
// true
// true

Reimplemented from xtd::object.

equals() [2/2]

template<typename type_t >

bool xtd::box< type_t >::equals ( const box< type_t > &  ) 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< box< type_t > >.

to_string() [1/3]

template<typename type_t >

xtd::string xtd::box< type_t >::to_string ( ) const

inlineoverridevirtualnoexcept

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

Returns

A string that represents the current object.

Examples

The following code example demonstrates what to_string returns.

#include <xtd/xtd>
 
using namespace xtd;
 
namespace examples {
  namespace object_test {
    class object1 : public object {
    };
  }
}
 
auto main() -> int {
  ptr<object> obj1 = new_ptr<examples::object_test::object1>();
  console::write_line(obj1->to_string());
 
  ptr<object> obj2 = new_ptr<date_time>(1971, 1, 5, 23, 5, 0);
  console::write_line(obj2->to_string());
 
  ptr<object> obj3 = new_ptr<boolean_object>();
  console::write_line(obj3->to_string());
}
 
// This code produces the following output :
//
// examples::object_test::object1
// Tue Jan  5 23:05:00 1971
// false

Reimplemented from xtd::object.

Examples

application_restart.cpp, console_out.cpp, and generic_ienumerable2.cpp.

to_string() [2/3]

template<typename type_t >

xtd::string xtd::box< type_t >::to_string ( const xtd::string &  format ) const

inline

Converts the value of this instance to its equivalent string representation, using the specified format.

Parameters

format

A value type format string.

Returns

The string representation of the value of this instance as specified by format.

to_string() [3/3]

template<typename type_t >

xtd::string xtd::box< type_t >::to_string ( const xtd::string &  format, const std::locale &  loc  ) const

inlineoverridevirtual

Converts the value of this instance to its equivalent string representation, using the specified format, and locale.

Parameters

format	A value type format string.
loc	An std::locale object that contains locale information (see std::locale).

Returns

The string representation of the value of this instance as specified by format.

Implements xtd::iformatable.

parse()

template<typename type_t >

static type_t xtd::box< type_t >::parse ( const xtd::string &  value )

inlinestatic

Converts the string to its type_t equivalent.

Parameters

value

A string containing a type_t to convert.

Returns

A type_t equivalent to the number contained in value.

try_parse()

template<typename type_t >

static bool xtd::box< type_t >::try_parse ( const xtd::string &  value, type_t &  result  )

inlinestaticnoexcept

Converts the string to its type_t equivalent. A return value indicates whether the conversion succeeded or failed.

Parameters

value	A string containing a type_t to convert.
result	A type_t equivalent to the number contained in value.

Returns

true if s was converted successfully; otherwise, false.

---

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

• xtd.core/include/xtd/box.hpp