xtd::collections::generic::params< type_t > Class Template Reference

Inheritance diagram for xtd::collections::generic::params< type_t >:

Definition

template<typename type_t>
class xtd::collections::generic::params< type_t >

An object of type xtd::collections::generic::params <type_t> is a lightweight proxy object that provides access to an array of objects of type const type_t (that may be allocated in read-only memory).

template<typename type_t>
class params : public xtd::object

Header

#include <xtd/collections/generic/params

Namespace

xtd::collections::generic

Library

xtd.core

Remarks

This class cannot be inherited.

A xtd::collections::generic::params object is automatically constructed when:

• A brace-enclosed params is used to initialize an object, where the corresponding constructor accepts an xtd::collections::generic::params or std::initializer_list parameter,
• A brace-enclosed params is used as the right operand of assignment or as a function call argument, and the corresponding assignment operator/function accepts an xtd::collections::generic::params or std::initializer_list parameter.
• A brace-enclosed params is bound to auto, including in a ranged for loop.

xtd::collections::generic::params may be implemented as a pair of pointers or pointer and length. Copying a xtd::collections::generic::params does not copy the backing array of the corresponding params.

xtd::collections::generic::params is exactly The same as std::initializer_list object.

Warning

When creating your own container, use the std::initializer_list object instead of the xtd::collections::generic::params object for the constructor, because C++ compilers use a magic trick (such as a private constructor) to initialize elements correctly. Use xtd::collections::generic::params when initializing elements yourself.

Examples

The following example demonstrates how to usea xtd::collections::generic::params <type_t> class.

#include <xtd/collections/generic/list>
#include <xtd/console>
#include <xtd/startup>
#include <xtd/time_span>
#include <vector>
 
using namespace xtd;
using namespace xtd::collections::generic;
 
class program {
public:
  static auto main() -> void {
    console::write_line("params = {}", params {1, 2, 3, 4, 5});
    console::write_line("list = {}", list<int> {params {1, 2, 3, 4, 5}});
    console::write_line("vector = {}", std::vector<int> {params {1, 2, 3, 4, 5}});
    console::write_line("create_list = {}", create_list(params {"one", "two", "three", "four", "five"}));
    console::write_line("create_vector = {}", create_vector(params {3_h + 2_min + 1_s, 3_h + 2_min + 2_s, 3_h + 2_min + 3_s, 3_h + 2_min + 4_s, 3_h + 2_min + 5_s}));
  }
  
private:
  template <typename type_t>
  static list<type_t> create_list(params<type_t> items) {
    return list<type_t> {items};
  }
  
  template <typename type_t>
  static std::vector<type_t> create_vector(params<type_t> items) {
    return std::vector<type_t> {items};
  }
  
};
 
startup_(program::main);
 
// This code can produce the following output :
//
// params = [1, 2, 3, 4, 5]
// list = [1, 2, 3, 4, 5]
// vector = [1, 2, 3, 4, 5]
// create_list = [1, 2, 3, 4, 5]
// create_vector = [03:02:01, 03:02:02, 03:02:03, 03:02:04, 03:02:05]

Public Alias
using	base_type = std::initializer_list< type_t >
	Represents the params base type.
using	value_type = typename base_type::value_type
	Represents the params value type.
using	reference = typename base_type::reference
	Represents the reference of params value type.
using	const_reference = typename base_type::const_reference
	Represents the const reference of params value type.
using	const_pointer = const value_type *
	Represents the const pointer of params value type.
using	size_type = typename base_type::size_type
	Represents the params size type (usually xtd::size).
using	iterator = typename base_type::iterator
	Represents the iterator of params value type.
using	const_iterator = typename base_type::const_iterator
	Represents the const iterator of params value type.

Public Constructors
constexpr	params () noexcept=default
	Create a new instance of the class xtd::collections::generic::params.

Public Properties
constexpr iterator	begin () const noexcept
	Returns a pointer to the first element in the params.
virtual const_pointer	data () const noexcept
	Returns pointer to the underlying array serving as element storage.
constexpr iterator	end () const noexcept
	Returns a pointer to one past the last element in the params, i.e. begin() + size().
virtual const base_type &	items () const noexcept
	Returns the underlying base type items.
constexpr size_type	size () const noexcept
	Returns the number of elements in the params, i.e. std::distance(begin(), end()).

Public Methods
xtd::string	to_string () const noexcept override
	Returns a xtd::string that represents the current object.

Public Operators
	operator const base_type & () const noexcept
	Returns a reference to the underlying base type.
	operator base_type & () noexcept
	Returns a reference to the underlying base type.

Additional Inherited Members
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current 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.
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.

Member Typedef Documentation

base_type

template<typename type_t >

using xtd::collections::generic::params< type_t >::base_type = std::initializer_list<type_t>

Represents the params base type.

value_type

template<typename type_t >

using xtd::collections::generic::params< type_t >::value_type = typename base_type::value_type

Represents the params value type.

reference

template<typename type_t >

using xtd::collections::generic::params< type_t >::reference = typename base_type::reference

Represents the reference of params value type.

const_reference

template<typename type_t >

using xtd::collections::generic::params< type_t >::const_reference = typename base_type::const_reference

Represents the const reference of params value type.

const_pointer

template<typename type_t >

using xtd::collections::generic::params< type_t >::const_pointer = const value_type*

Represents the const pointer of params value type.

size_type

template<typename type_t >

using xtd::collections::generic::params< type_t >::size_type = typename base_type::size_type

Represents the params size type (usually xtd::size).

iterator

template<typename type_t >

using xtd::collections::generic::params< type_t >::iterator = typename base_type::iterator

Represents the iterator of params value type.

const_iterator

template<typename type_t >

using xtd::collections::generic::params< type_t >::const_iterator = typename base_type::const_iterator

Represents the const iterator of params value type.

Constructor & Destructor Documentation

params()

template<typename type_t >

constexpr xtd::collections::generic::params< type_t >::params ( )

constexprdefaultnoexcept

Create a new instance of the class xtd::collections::generic::params.

Member Function Documentation

begin()

template<typename type_t >

constexpr iterator xtd::collections::generic::params< type_t >::begin ( ) const

inlineconstexprnoexcept

Returns a pointer to the first element in the params.

Returns

A pointer to the first element in the params.

Remarks

If the params is empty, the values of begin() and end() are unspecified, but will be identical.

data()

template<typename type_t >

virtual const_pointer xtd::collections::generic::params< type_t >::data ( ) const

inlinevirtualnoexcept

Returns pointer to the underlying array serving as element storage.

Returns

Pointer to the underlying element storage. For non-empty containers, the returned pointer compares equal to the address of the first element.

Remarks

The pointer is such that range [xtd::collections::generic::list::data(), xtd::collections::generic::list::data() + xtd::collections::generic::list::size()) is always a valid range, even if the container is empty (xtd::collections::generic::list::data() is not dereferenceable in that case).

end()

template<typename type_t >

constexpr iterator xtd::collections::generic::params< type_t >::end ( ) const

inlineconstexprnoexcept

Returns a pointer to one past the last element in the params, i.e. begin() + size().

Returns

A pointer to one past the last element in the params.

Remarks

If the params is empty, the values of begin() and end() are unspecified, but will be identical.

items()

template<typename type_t >

virtual const base_type & xtd::collections::generic::params< type_t >::items ( ) const

inlinevirtualnoexcept

Returns the underlying base type items.

Returns

The underlying base type items.

size()

template<typename type_t >

constexpr size_type xtd::collections::generic::params< type_t >::size ( ) const

inlineconstexprnoexcept

Returns the number of elements in the params, i.e. std::distance(begin(), end()).

Returns

The number of elements in the params.

to_string()

template<typename type_t >

xtd::string xtd::collections::generic::params< 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.

operator const base_type &()

template<typename type_t >

xtd::collections::generic::params< type_t >::operator const base_type & ( ) const

inlinenoexcept

Returns a reference to the underlying base type.

Returns

Reference to the underlying base type.

operator base_type &()

template<typename type_t >

xtd::collections::generic::params< type_t >::operator base_type & ( )

inlinenoexcept

Returns a reference to the underlying base type.

Returns

Reference to the underlying base type.

---

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

• xtd.core/include/xtd/collections/generic/params.h