xtd::enum_register< enum_t > Struct Template Reference

#include <enum_register.h>

Definition

template<typename enum_t>
struct xtd::enum_register< enum_t >

Provides the registration struct for enumerations.

template<typename enum_t>
struct enum_register

Namespace

xtd

Library

xtd.core

Remarks

The overloading of this operator is necessary for enum classes to be recognized by xtd::ustring::format().

For more information about enumeration, see enum class guide.

When an enumeration is registered, we can display its name instead of its value, we can format it and parse it.

See Enumeration Format Strings. For more information about formatting in general, see Formatting Types.

Examples

The following code show how to use xtd::enum_register operator for an enum.

#include <xtd/xtd>

using namespace xtd;

enum class enum_test {
  value_one,
  value_two,
  value_three,
  value_four
};

template<> struct xtd::enum_register<enum_test> {
  explicit operator auto() const noexcept {return xtd::enum_collection<enum_test> {{enum_test::value_one, "value_one"}, {enum_test::value_two, "value_two"}, {enum_test::value_three, "value_three"}, {enum_test::value_four, "value_four"}};}
};

auto main()->int {
  console::write_line("name = {}", enum_test::value_four);
  console::write_line("value = {}", enum_object(enum_test::value_four).to_int32());
  console::write_line("as<int> = {}", as<int>(enum_test::value_four));
  console::write_line("values = {}", enum_object<>::get_values_as_int32<enum_test>());
  console::write_line("names = {}", enum_object<>::get_names<enum_test>());
  console::write_line("entries = {}", enum_object<>::get_entries_as_int32<enum_test>());
}

// This code produces the following output :
//
// name = value_four
// value = 3
// as<int> = 3
// values = [0, 1, 2, 3]
// names = [value_one, value_two, value_three, value_four]
// entries = [(0, value_one), (1, value_two), (2, value_three), (3, value_four)]

The following code show how to use xtd::enum_register operator for an enum flags.

#include <xtd/xtd>

using namespace xtd;

enum class text_attribute {
  normal = 0b0,
  bold = 0b1,
  italic = 0b10,
  underline = 0b100,
  strikeout = 0b1000
};

text_attribute operator|(text_attribute lhs, text_attribute rhs) {return static_cast<text_attribute>(static_cast<std::underlying_type<text_attribute>::type>(lhs) | static_cast<std::underlying_type<text_attribute>::type>(rhs));}

template<> struct xtd::enum_set_attribute<text_attribute> {
  explicit operator auto() const noexcept {return xtd::enum_attribute::flags;}
};

template<> struct xtd::enum_register<text_attribute> {
  explicit operator auto() const noexcept {return xtd::enum_collection<text_attribute> {{text_attribute::normal, "normal"}, {text_attribute::bold, "bold"}, {text_attribute::italic, "italic"}, {text_attribute::underline, "underline"}, {text_attribute::strikeout, "strikeout"}};}
};

auto main()->int {
  console::write_line("name = {}", text_attribute::bold | text_attribute::italic);
  console::write_line("value = {}", enum_object(text_attribute::bold | text_attribute::italic).to_int32());
  console::write_line("as<int> = {}", as<int>(text_attribute::bold | text_attribute::italic));
  console::write_line("values = {}", enum_object<>::get_values_as_int32<text_attribute>());
  console::write_line("names = {}", enum_object<>::get_names<text_attribute>());
  console::write_line("entries = {}", enum_object<>::get_entries_as_int32<text_attribute>());
}

Examples:

enum_class_flags_without_helpers.cpp, enum_class_without_helper.cpp, format_enum.cpp, format_enum_class.cpp, format_enum_class_flags.cpp, and format_enum_class_flags_without_helper.cpp.

Public Member Functions
	operator auto () const noexcept

Member Function Documentation

operator auto()

template<typename enum_t >

xtd::enum_register< enum_t >::operator auto ( ) const

inlineexplicitnoexcept

Allows to register an enumeration that can be used by xtd::enum_object.

Returns

An xtd::enum_collection collection that represent enumeration.

Remarks

To register an enumeration just override xtd::enum_register.

Examples

The following code show how to register the values enum class.

enum class values {
  value_one,
  value_two
};

template<>
xtd::enum_register<values> {
  explicit operator auto() const noexcept {return xtd::enum_collection<values> {{values::value_one, "value_one"}, {values::value_two, "value_two"}};}
};

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

• xtd.core/include/xtd/enum_register.h