Description

A record class that holds named elements in a generic way.

Motivation

A set of name-type pairs, for example { age : int, name : string }, is generally called a record. In C++, these are usually declared using classes or structs:

struct person
{
  int age;
  std::string name;
};

The shortcoming is that such a struct provides no generic structure. Imagine you would like to write a generic function that prints such a struct, given you already know how to print ints and strings. A concrete implementation would look like this:

void print(std::ostream &_stream, person const &_person)
{
  _stream << "age: " << _person.age << ", "
          << "name: " << _person.name;
}

This, however, only works for the concrete type person. To find a more abstract representation, we need to specify which elements a struct has in a generic way. To this end, we first of all need to create unique types that represent element names which we call labels. Such a label together with a unique tag type is created by FCPPT_RECORD_MAKE_LABEL:

// age = fcppt::record::label<T> for a unique tag type T
FCPPT_RECORD_MAKE_LABEL(age);
 
// name = fcppt::record::label<T> for a unique tag type T
FCPPT_RECORD_MAKE_LABEL(name);

A record element is represented by fcppt::record::element. It gets a label together with a type as its template parameters:

using age_element = fcppt::record::element<age, int>;
 
using name_element = fcppt::record::element<name, std::string>;

Finally, a record object consists of a list of elements:

using person = fcppt::record::object<age_element, name_element>;

Before we continue, here is a small example of how to use such a record:

  person test_person{age{} = 1, name{} = std::string("test")};
 
  std::cout << fcppt::record::get<age>(test_person) << '\n';
 
  fcppt::record::set<age>(test_person, 2);
 
  std::cout << fcppt::record::get<age>(test_person) << '\n';

The initialization syntax is further explained in Initialization. The functions fcppt::record::get and fcppt::record::set are used to read and write elements.

To return to our goal of creating a generic output function, we first create a function print_label that given a record and a label prints the element for the given label to a stream:

template <typename Label, typename... Elements>
void print_label(std::ostream &_stream, fcppt::record::object<Elements...> const &_record)
{
  _stream
      // extract the label name
      << fcppt::record::label_name<Label>()
      << ": "
      // extract the value for the label
      << fcppt::record::get<Label>(_record) << ", ";
}

The function fcppt::record::element_vector returns an fcppt::mpl::list::object of the elements of a record. Such a list can be used by fcppt::algorithm::loop, which will call a function for every type in the sequence. We use this to call print_label for every element of the record:

template <typename... Elements>
void print(std::ostream &_stream, fcppt::record::object<Elements...> const &_record)
{
  // Loop over all types in the record
  fcppt::algorithm::loop(
      fcppt::record::element_vector<fcppt::record::object<Elements...>>{},
      [&_stream, &_record]<typename L, typename T>(fcppt::tag<fcppt::record::element<L, T>>)
      { print_label<L>(_stream, _record); });
}

Now, if we were to add another member to the person record, say address, we wouldn't have to change our print function.

Initialization

There are two ways to initialize a record: First, we can initialize every element separately. This is done by the special syntax

record{label_1{} = value_1, ..., label_n{} = value_n}

Here, it is important that all labels of the record appear exactly once. Also, the types of the values have to match the types of the record.

person const test_person{
        age{} = 42
        // error: forgotten name
};
 
person const test_person{
        // error: age specified twice
        age{} = 42,
        age{} = 10
};
 
person const test_person{
        age{} = 42,
        name{} = 10 // error: wrong type for name
};

The second way to initialize a record is via the fcppt::record::init function. It is a generic function that calls a function for every element of the record (from first to last), which can be used to initialize a record in a generic way. Assume that we have the values for our record in a stream:

std::istringstream stream{"42 test"};

We then read the corresponding elements of the record from the stream:

  person const result{fcppt::record::init<person>(
      [&stream]<typename L, typename T>(fcppt::record::element<L, T>)
      {
        T input;
 
        if (!(stream >> input))
        {
          throw std::runtime_error{"failure"};
        }
 
        return input;
      })};

The lambda is first called for age_element and second for name_element because of the order they appear in the declaration. So, in the example, age will be 42 and name will be "test".

Labels with an argument

Unlike normal labels, there are also labels that take an additional argument. Consider a sprite that can have a fixed number of textures t_1,...,t_n which will be rendered in order. To create a label that is parameterized, we use FCPPT_RECORD_MAKE_LABEL_ARG:

// Parametrize the texture label with an unsigned int.
// template<unsigned I> using texture = fcppt::record::label<T,I> for a unique tag type T
FCPPT_RECORD_MAKE_LABEL_ARG(texture, unsigned);

Next, we create a type function that takes an unsigned integer I to the I'th texture element:

template <unsigned I>

using sprite_element = fcppt::record::element<texture<I>, std::string>;

Finally, to declare our sprite with N textures, we use a std::integer_sequence to create a record with types sprite_element<0>, ..., sprite_element<N-1>.

template <typename T>
struct sprite_from_ints;
 
template <unsigned... Ints>
struct sprite_from_ints<std::integer_sequence<unsigned, Ints...>>
{
  using type = fcppt::record::object<sprite_element<Ints>...>;
};
 
template <unsigned N>
using sprite = typename sprite_from_ints<std::make_integer_sequence<unsigned, N>>::type;

Here is an example that shows how such a sprite can be initialized:

  using sprite_type = sprite<2U>;
 
  sprite_type const test_sprite{
      texture<0>{} = std::string("ground"), texture<1>{} = std::string("clouds")};

Header files

Header file	Description
`object_fwd.hpp`	Contains fcppt::record::object record's declaration.
`object_decl.hpp`	Contains fcppt::record::object record's definition.
`object_impl.hpp`	Contains the definition of fcppt::record::object record's member functions.
`object.hpp`	Includes `object_impl.hpp` and `comparison.hpp`.
`comparison.hpp`	Contains `operator==` and `operator!=`.
`element_fwd.hpp`	Contains fcppt::record::element element's declaration.
`element.hpp`	Contains fcppt::record::element element's definition.
`element_to_label.hpp`	Contains fcppt::record::element_to_label.
`element_to_type.hpp`	Contains fcppt::record::element_to_type.
`from_list_fwd.hpp`	Contains fcppt::record::from_list.
`from_list.hpp`	Includes `fcppt/record/from_list_fwd.hpp` and defines fcppt::record::object.
`get.hpp`	Contains fcppt::record::get.
`init.hpp`	Contains fcppt::record::init.
`label_fwd.hpp`	Contains fcppt::record::label label's declaration.
`label_decl.hpp`	Contains fcppt::record::label label's definition.
`label_impl.hpp`	Contains the definition of fcppt::record::label label's member functions.
`label.hpp`	Includes `label_impl.hpp`.
`label_name.hpp`	Contains fcppt::record::label_name.
`label_value_type.hpp`	Contains fcppt::record::label_value_type.
`make_label_fwd.hpp`	Contains FCPPT_RECORD_MAKE_LABEL and includes `label_fwd.hpp`.
`make_label.hpp`	Includes `make_label_fwd.hpp` and `label_impl.hpp`.
`make_label_arg_fwd.hpp`	Contains FCPPT_RECORD_MAKE_LABEL_ARG and includes `label_fwd.hpp`.
`make_label_arg.hpp`	Includes `make_label_arg_fwd.hpp` and `label_impl.hpp`.
`output.hpp`	Contains `operator<<` .
`set.hpp`	Contains fcppt::record::set.

Classes
struct	fcppt::record::element< Label, Type >
	An element of a record. More...

class	fcppt::record::element_init< Tag, Type >
	The type produced by initializing a single record element. More...

struct	fcppt::record::is_element< typename >
	Tests if a type is an fcppt::record::element. More...

struct	fcppt::record::is_label< typename >
	Tests if a type is an fcppt::record::label. More...

struct	fcppt::record::is_object< T >
	Tests if a type is an fcppt::record::object. More...

struct	fcppt::record::label< Tag >
	A type identifying an element of a record. More...

class	fcppt::record::object< Elements >
	A generic struct that identifies elements by types. More...

Macros
#define	FCPPT_RECORD_MAKE_LABEL_ARG(name, arg)
	Creates a parametrized fcppt::record::label.

#define	FCPPT_RECORD_MAKE_LABEL(name)
	Creates an fcppt::record::label.

Typedefs
template<fcppt::mpl::list::object_concept List>
using	fcppt::mpl::list::unique = fcppt::mpl::set::to_list< fcppt::mpl::set::from_list_relaxed< List > >
	Removes duplicates from a list.

template<fcppt::mpl::list::object_concept Records>
using	fcppt::record::all_disjoint = std::is_same< fcppt::mpl::set::size< fcppt::mpl::list::fold< Records, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::mpl::set::union_ >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::label_set >, fcppt::mpl::arg< 1 > >, fcppt::mpl::arg< 2 > >, fcppt::mpl::set::object<> > >, fcppt::mpl::list::size< fcppt::mpl::list::join< fcppt::mpl::list::map< Records, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::mpl::set::to_list >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::label_set >, fcppt::mpl::arg< 1 > > > > > > >
	Tests if multiple records have disjoint label sets.

template<typename RecordL , typename RecordR >
using	fcppt::record::are_disjoint = std::is_same< fcppt::mpl::set::intersection< fcppt::record::label_set< RecordL >, fcppt::record::label_set< RecordR > >, fcppt::mpl::set::object<> >
	Tests if two records have disjoint label sets.

template<typename Record1 , typename Record2 >
using	fcppt::record::are_equivalent = fcppt::mpl::map::equal< fcppt::record::element_map< Record1 >, fcppt::record::element_map< Record2 > >
	Tests if two records have the same element maps.

template<typename RecordL , typename RecordR >
using	fcppt::record::disjoint_product = typename fcppt::record::detail::disjoint_product< RecordL, RecordR >::type
	The product of two disjoint records.

template<typename Type >
using	fcppt::record::element_init_tag = typename fcppt::record::detail::element_init_tag< Type >::type
	The tag type of fcppt::record::element_init.

template<typename Type >
using	fcppt::record::element_init_type = typename fcppt::record::detail::element_init_type< Type >::type
	The value type of fcppt::record::element_init.

template<typename Record >
using	fcppt::record::element_map = fcppt::mpl::list::fold< fcppt::record::element_vector< Record >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::mpl::map::insert >, fcppt::mpl::arg< 2 >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::element_to_label >, fcppt::mpl::arg< 1 > >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::element_to_type >, fcppt::mpl::arg< 1 > > >, fcppt::mpl::map::object<> >
	A metafunction computing the element map of a record.

template<typename Record >
using	fcppt::record::element_tag_tuple = fcppt::mpl::list::as_tuple< fcppt::mpl::list::map< fcppt::record::element_vector< Record >, fcppt::mpl::lambda< fcppt::tag > > >
	A metafunction returning the elements of record as a `fcppt::tuple::object` of `fcppt::tag` types.

template<typename Element >
using	fcppt::record::element_to_label = typename fcppt::record::detail::element_to_label< Element >::type
	Extracts the type of an fcppt::record::element.

template<typename Element >
using	fcppt::record::element_to_type = typename fcppt::record::detail::element_to_type< std::remove_cv_t< Element > >::type
	Extracts the label of an element.

template<typename Record >
using	fcppt::record::element_vector = typename fcppt::record::detail::element_vector< Record >::type
	A metafunction returning the elements of record as an MPL vector.

template<typename... Args>
using	fcppt::record::enable_vararg_ctor = std::enable_if_t< std::conjunction_v< fcppt::record::detail::is_element_init< std::remove_cvref_t< Args > >... > >
	Checks if a parameter pack is suitable for record initialization.

template<fcppt::mpl::list::object_concept List>
using	fcppt::record::from_list = fcppt::mpl::list::as< fcppt::record::object, List >
	Declares a record using an mpl::list.

template<typename Record , typename Label >
using	fcppt::record::has_label = fcppt::mpl::set::contains< fcppt::record::label_set< Record >, Label >
	Tests if a record has an fcppt::record::label.

template<typename Record >
using	fcppt::record::label_set = fcppt::mpl::set::from_list_relaxed< fcppt::record::detail::label_list< fcppt::record::element_vector< Record > > >
	The set of labels of a record.

template<typename Record , typename Label >
using	fcppt::record::label_value_type = fcppt::record::element_to_type< fcppt::record::detail::find_element< fcppt::record::element_vector< Record >, Label > >
	Metafunction that computes the value type of a label inside a record.

template<typename Record , typename Function >
using	fcppt::record::map_elements = fcppt::record::from_list< fcppt::mpl::list::map< fcppt::record::element_vector< Record >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::element >, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::element_to_label >, fcppt::mpl::arg< 1 > >, Function > > >
	Maps the elements of a vector using a metafunction.

template<typename Record , typename Function >
using	fcppt::record::map_result = fcppt::record::map_elements< Record, fcppt::mpl::bind< fcppt::mpl::lambda< fcppt::record::detail::map_result >, fcppt::mpl::constant< Function >, fcppt::mpl::arg< 1 > > >
	The result of mapping a record.

Functions
template<typename... Types1, typename... Types2>
bool	fcppt::record::operator== (fcppt::record::object< Types1... > const &_record1, fcppt::record::object< Types2... > const &_record2)
	Compares two records for equality.

template<typename... Types1, typename... Types2>
bool	fcppt::record::operator!= (fcppt::record::object< Types1... > const &_record1, fcppt::record::object< Types2... > const &_record2)
	Compares two records for inequality.

template<typename Label , typename... Elements>
fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > const &	fcppt::record::get (fcppt::record::object< Elements... > const &_arg)
	Gets an element from a record.

template<typename Label , typename... Elements>
fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > &	fcppt::record::get (fcppt::record::object< Elements... > &_arg)
	Gets an element from a record.

template<typename Result , typename Function >
Result	fcppt::record::init (Function const &_function)
	Initializes a record using a function.

template<typename Label >
std::string	fcppt::record::label_name ()
	Returns the name of a label as a string.

template<typename... Args, typename = fcppt::record::enable_vararg_ctor<Args...>> requires (fcppt::mpl::list::distinct< fcppt::mpl::list::object<fcppt::record::label<fcppt::record::element_init_tag<Args>>...>>::value)
fcppt::record::object< fcppt::record::element< fcppt::record::label< fcppt::record::element_init_tag< Args > >, fcppt::record::element_init_type< Args > >... >	fcppt::record::make (Args &&..._args)
	Creates a record from an initializer list.

template<typename Record , typename Function >
fcppt::record::map_result< Record, Function >	fcppt::record::map (Record &&_record, Function const &_function)
	Maps a record using a function.

template<typename Record1 , typename Record2 >
fcppt::record::disjoint_product< std::remove_cvref_t< Record1 >, std::remove_cvref_t< Record2 > >	fcppt::record::multiply_disjoint (Record1 &&_record1, Record2 &&_record2)
	Creates the disjoint product of two records.

template<typename Ch , typename Traits , typename... Elements>
std::basic_ostream< Ch, Traits > &	fcppt::record::operator<< (std::basic_ostream< Ch, Traits > &_stream, fcppt::record::object< Elements... > const &_record)
	Outputs a record to a stream.

template<typename Result , typename Arg >
Result	fcppt::record::permute (Arg &&_arg)
	Permutes one record into another.

template<typename Label , typename... Elements>
void	fcppt::record::set (fcppt::record::object< Elements... > &_arg, fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > const &_value)
	Sets an element in a record by copy.

template<typename Label , typename... Elements>
void	fcppt::record::set (fcppt::record::object< Elements... > &_arg, fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > &&_value)
	Sets an element in a record by move.

Macro Definition Documentation

◆ FCPPT_RECORD_MAKE_LABEL

#define FCPPT_RECORD_MAKE_LABEL ( name )

Value:

  FCPPT_RECORD_DETAIL_MAKE_TAG(name); \
\
  using name = fcppt::record::label<FCPPT_RECORD_DETAIL_TAG_NAME(name)>

Creates an fcppt::record::label.

Creates an fcppt::record::label, passing it a unique, implementation-defined tag type.

Parameters

name	The name of the label type.

◆ FCPPT_RECORD_MAKE_LABEL_ARG

#define FCPPT_RECORD_MAKE_LABEL_ARG	(	name,
		arg
	)

Value:

  template <arg> \
  FCPPT_RECORD_DETAIL_MAKE_TAG(name); \
\
  template <arg arg_name> \
  using name = fcppt::record::label<FCPPT_RECORD_DETAIL_TAG_NAME(name) < arg_name>\
 >

Creates a parametrized fcppt::record::label.

Creates an fcppt::record::label, passing it a unique, implementation-defined tag type that depends on a template parameter. The result is a template alias that still takes a parameter of type arg.

Parameters

name	The name of the label type.
arg	The type of the template parameter.

Typedef Documentation

◆ all_disjoint

template<fcppt::mpl::list::object_concept Records>

using fcppt::record::all_disjoint = typedef std::is_same< fcppt::mpl::set::size<fcppt::mpl::list::fold< Records, fcppt::mpl::bind< fcppt::mpl::lambda<fcppt::mpl::set::union_>, fcppt::mpl::bind<fcppt::mpl::lambda<fcppt::record::label_set>, fcppt::mpl::arg<1> >, fcppt::mpl::arg<2> >, fcppt::mpl::set::object<> >>, fcppt::mpl::list::size<fcppt::mpl::list::join<fcppt::mpl::list::map< Records, fcppt::mpl::bind< fcppt::mpl::lambda<fcppt::mpl::set::to_list>, fcppt::mpl::bind<fcppt::mpl::lambda<fcppt::record::label_set>, fcppt::mpl::arg<1> >> >> >>

Tests if multiple records have disjoint label sets.

◆ are_disjoint

template<typename RecordL , typename RecordR >

using fcppt::record::are_disjoint = typedef std::is_same< fcppt::mpl::set:: intersection<fcppt::record::label_set<RecordL>, fcppt::record::label_set<RecordR> >, fcppt::mpl::set::object<> >

Tests if two records have disjoint label sets.

◆ are_equivalent

template<typename Record1 , typename Record2 >

using fcppt::record::are_equivalent = typedef fcppt::mpl:: map::equal<fcppt::record::element_map<Record1>, fcppt::record::element_map<Record2> >

Tests if two records have the same element maps.

◆ disjoint_product

template<typename RecordL , typename RecordR >

using fcppt::record::disjoint_product = typedef typename fcppt::record::detail::disjoint_product<RecordL, RecordR>::type

The product of two disjoint records.

◆ element_init_tag

template<typename Type >

using fcppt::record::element_init_tag = typedef typename fcppt::record::detail::element_init_tag<Type>::type

The tag type of fcppt::record::element_init.

◆ element_init_type

template<typename Type >

using fcppt::record::element_init_type = typedef typename fcppt::record::detail::element_init_type<Type>::type

The value type of fcppt::record::element_init.

◆ element_map

template<typename Record >

using fcppt::record::element_map = typedef fcppt::mpl::list::fold< fcppt::record::element_vector<Record>, fcppt::mpl::bind< fcppt::mpl::lambda<fcppt::mpl::map::insert>, fcppt::mpl::arg<2>, fcppt::mpl::bind<fcppt::mpl::lambda<fcppt::record::element_to_label>, fcppt::mpl::arg<1> >, fcppt::mpl::bind<fcppt::mpl::lambda<fcppt::record::element_to_type>, fcppt::mpl::arg<1> >>, fcppt::mpl::map::object<> >

A metafunction computing the element map of a record.

Template Parameters

Record Must be an fcppt::record::object.

◆ element_tag_tuple

template<typename Record >

using fcppt::record::element_tag_tuple = typedef fcppt::mpl::list::as_tuple< fcppt::mpl::list::map<fcppt::record::element_vector<Record>, fcppt::mpl::lambda<fcppt::tag> >>

A metafunction returning the elements of record as a fcppt::tuple::object of fcppt::tag types.

Template Parameters

Record Must be an fcppt::record::object.

◆ element_to_label

template<typename Element >

using fcppt::record::element_to_label = typedef typename fcppt::record::detail::element_to_label<Element>::type

Extracts the type of an fcppt::record::element.

Template Parameters

Element Must be an fcppt::record::element.

◆ element_to_type

template<typename Element >

using fcppt::record::element_to_type = typedef typename fcppt::record::detail::element_to_type<std::remove_cv_t<Element> >::type

Extracts the label of an element.

Template Parameters

Element Must be an fcppt::record::element.

◆ element_vector

template<typename Record >

using fcppt::record::element_vector = typedef typename fcppt::record::detail::element_vector<Record>::type

A metafunction returning the elements of record as an MPL vector.

Template Parameters

Record Must be an fcppt::record::object.

◆ enable_vararg_ctor

template<typename... Args>

using fcppt::record::enable_vararg_ctor = typedef std::enable_if_t<std::conjunction_v< fcppt::record::detail::is_element_init<std::remove_cvref_t<Args> >...> >

Checks if a parameter pack is suitable for record initialization.

◆ from_list

template<fcppt::mpl::list::object_concept List>

using fcppt::record::from_list = typedef fcppt::mpl::list::as<fcppt::record::object, List>

Declares a record using an mpl::list.

◆ has_label

template<typename Record , typename Label >

using fcppt::record::has_label = typedef fcppt::mpl::set::contains<fcppt::record::label_set<Record>, Label>

Tests if a record has an fcppt::record::label.

◆ label_set

template<typename Record >

using fcppt::record::label_set = typedef fcppt::mpl::set::from_list_relaxed< fcppt::record::detail::label_list<fcppt::record::element_vector<Record> >>

The set of labels of a record.

Template Parameters

Record Must be an fcppt::record::object.

◆ label_value_type

template<typename Record , typename Label >

using fcppt::record::label_value_type = typedef fcppt::record::element_to_type< fcppt::record::detail::find_element<fcppt::record::element_vector<Record>, Label> >

Metafunction that computes the value type of a label inside a record.

Returns the type the label Label has in Record.

◆ map_elements

template<typename Record , typename Function >

using fcppt::record::map_elements = typedef fcppt::record::from_list<fcppt::mpl::list::map< fcppt::record::element_vector<Record>, fcppt::mpl::bind< fcppt::mpl::lambda<fcppt::record::element>, fcppt::mpl::bind<fcppt::mpl::lambda<fcppt::record::element_to_label>, fcppt::mpl::arg<1> >, Function> >>

Maps the elements of a vector using a metafunction.

Template Parameters

Record	Must be an fcppt::record::object.
Function	A metafunction accepting fcppt::record::element as parameter and returning the new mapped type.

◆ map_result

template<typename Record , typename Function >

using fcppt::record::map_result = typedef fcppt::record::map_elements< Record, fcppt::mpl::bind< fcppt::mpl::lambda<fcppt::record::detail::map_result>, fcppt::mpl::constant<Function>, fcppt::mpl::arg<1> >>

The result of mapping a record.

◆ unique

template<fcppt::mpl::list::object_concept List>

using fcppt::mpl::list::unique = typedef fcppt::mpl::set::to_list<fcppt::mpl::set::from_list_relaxed<List> >

Removes duplicates from a list.

Function Documentation

◆ get() [1/2]

template<typename Label , typename... Elements>

fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > & fcppt::record::get ( fcppt::record::object< Elements... > & _arg )

inline

Gets an element from a record.

Returns the element identified by Label from _arg.

◆ get() [2/2]

template<typename Label , typename... Elements>

fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > const & fcppt::record::get ( fcppt::record::object< Elements... > const & _arg )

inline

Gets an element from a record.

Returns the element identified by Label from _arg.

◆ init()

template<typename Result , typename Function >

Result fcppt::record::init ( Function const & _function )

inline

Initializes a record using a function.

Let element<L_1,T_1>, ..., element<L_n,T_n> be the elements of Result. _function is then called as (element<L_i,T_i>) for i = 1,..,n.

Template Parameters

Result	Must be an fcppt::record::object.
Function	A polymorphic function callable as `fcppt::record::label_value_type<Result, L> (fcppt::record::element<L,T>)` for every `element<L,T>` in Result.

◆ label_name()

template<typename Label >

std::string fcppt::record::label_name ( )

inline

Returns the name of a label as a string.

◆ make()

template<typename... Args, typename = fcppt::record::enable_vararg_ctor<Args...>>
requires (fcppt::mpl::list::distinct< fcppt::mpl::list::object<fcppt::record::label<fcppt::record::element_init_tag<Args>>...>>::value)

fcppt::record::object< fcppt::record::element< fcppt::record::label< fcppt::record::element_init_tag< Args > >, fcppt::record::element_init_type< Args > >... > fcppt::record::make ( Args &&... _args )

inline

Creates a record from an initializer list.

Args must be created using label{} = value expressions.

◆ map()

template<typename Record , typename Function >

fcppt::record::map_result< Record, Function > fcppt::record::map	(	Record &&	_record,
		Function const &	_function
	)

inline

Maps a record using a function.

For every fcppt::record::element<L,T> in Record, _function(get<L>(_record)) is stored in the result type.

Template Parameters

Record	An fcppt::record::object.
Function	a polymorphic function that can be called with every type in Record.

See also: fcppt::record::map_result

◆ multiply_disjoint()

template<typename Record1 , typename Record2 >

fcppt::record::disjoint_product< std::remove_cvref_t< Record1 >, std::remove_cvref_t< Record2 > > fcppt::record::multiply_disjoint	(	Record1 &&	_record1,
		Record2 &&	_record2
	)

Creates the disjoint product of two records.

Template Parameters

Record1	Must be an fcppt::record::object that is disjoint from Record2.
Record2	Must be an fcppt::record::object that is disjoint from Record1.

◆ operator!=()

template<typename... Types1, typename... Types2>

bool fcppt::record::operator!=	(	fcppt::record::object< Types1... > const &	_record1,
		fcppt::record::object< Types2... > const &	_record2
	)

inline

Compares two records for inequality.

Template Parameters

Types1	Must be equivalent to Types2
Types2	Must be equivalent to Types1

◆ operator<<()

template<typename Ch , typename Traits , typename... Elements>

std::basic_ostream< Ch, Traits > & fcppt::record::operator<<	(	std::basic_ostream< Ch, Traits > &	_stream,
		fcppt::record::object< Elements... > const &	_record
	)

Outputs a record to a stream.

◆ operator==()

template<typename... Types1, typename... Types2>

bool fcppt::record::operator==	(	fcppt::record::object< Types1... > const &	_record1,
		fcppt::record::object< Types2... > const &	_record2
	)

Compares two records for equality.

Template Parameters

Types1	Must be equivalent to Types2
Types2	Must be equivalent to Types1

◆ permute()

template<typename Result , typename Arg >

Result fcppt::record::permute ( Arg && _arg )

inline

Permutes one record into another.

Template Parameters

Result	Must be equivalent to Arg, and must be an fcppt::record::object.
Arg	Must be equivalent to Result, and must be an fcppt::record::object.

◆ set() [1/2]

template<typename Label , typename... Elements>

void fcppt::record::set	(	fcppt::record::object< Elements... > &	_arg,
		fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > &&	_value
	)

inline

Sets an element in a record by move.

Moves _value to the element identified by Label in _arg.

◆ set() [2/2]

template<typename Label , typename... Elements>

void fcppt::record::set	(	fcppt::record::object< Elements... > &	_arg,
		fcppt::record::label_value_type< fcppt::record::object< Elements... >, Label > const &	_value
	)

inline

Sets an element in a record by copy.

Copies _value to the element identified by Label in _arg.

	4.4.0
Freundlich's C++ toolkit

Description

Motivation

Initialization

Labels with an argument

Header files

Classes

Macros

Typedefs

Functions

Macro Definition Documentation

◆ FCPPT_RECORD_MAKE_LABEL

◆ FCPPT_RECORD_MAKE_LABEL_ARG

Typedef Documentation

◆ all_disjoint

◆ are_disjoint

◆ are_equivalent

◆ disjoint_product

◆ element_init_tag

◆ element_init_type

◆ element_map

◆ element_tag_tuple

◆ element_to_label

◆ element_to_type

◆ element_vector

◆ enable_vararg_ctor

◆ from_list

◆ has_label

◆ label_set

◆ label_value_type

◆ map_elements

◆ map_result

◆ unique

Function Documentation

◆ get() [1/2]

◆ get() [2/2]

◆ init()

◆ label_name()

◆ make()

◆ map()

◆ multiply_disjoint()

◆ operator!=()

◆ operator<<()

◆ operator==()

◆ permute()

◆ set() [1/2]

◆ set() [2/2]