Compile-time reflection for aggregate types. More...

Classes
struct	any_type
	Type that can be implicitly converted to any type. More...

struct	cptr
	Wrapper of pointer type. More...

Typedefs
template<typename T , std::size_t N>
using	type_of = std::remove_cvref_t< std::tuple_element_t< N, decltype(to_tuple(fake_obj< T >))> >
	Type of N-th member of a default-constructible aggregate type `T`. More...

template<typename T , conststr::cstr Name>
using	type_of_member = type_of< T, index_of< T, Name > >
	Get the type of the member by its name. More...

Functions
template<typename T , typename... Args> requires (std::is_aggregate_v<std::remove_cvref_t<T>> && std::is_default_constructible_v<std::remove_cvref_t<T>>)
consteval std::size_t	number_of_members_impl ()
	Internal implementation of `number_of_members`. Get The number of a default-constructible aggregate type's members. More...

template<class T , std::size_t N = number_of_members<T>> requires (N <= 128)
constexpr decltype(auto)	to_tuple (T &&t)
	Convert a value of type `T` to a tuple containing references to all its members. More...

template<typename T , std::size_t N>
consteval auto	cptr_of_member ()
	Get the pointer of the N-th member as a constexpr value. More...

template<cptr Ptr>
consteval auto	pretty_name ()
	Core function to get member name via compiler built-in macro. More...

template<conststr::cstr Name>
consteval auto	basename_of_impl ()
	Internal implementation of `basename_of`. get the Base name of a full qualified name. More...

template<cptr Ptr>
consteval auto	name_of_ptr_impl ()
	Internal implementation of `name_of_ptr`. Extract the real name from the output of `pretty_name()`. More...

template<typename T , conststr::cstr Name, std::size_t SrchIdx> requires (number_of_members<T> > SrchIdx)
constexpr size_t	index_of_impl ()
	Internal implementation of `index_of`. Get the index of the member by its name. More...

template<std::size_t N, typename T >
constexpr decltype(auto)	member_of (T &&t)
	Get member reference of object `t`. More...

template<conststr::cstr Name, typename T > requires std::same_as<typename decltype(Name)::value_type, char>
constexpr decltype(auto)	member_of (T &&t)
	Get member reference of object `t` via member's name. More...

Variables
template<typename T >
const T	fake_obj
	An object of `T` that can be used in constant context without really construct it. More...

template<typename T >
constexpr std::size_t	number_of_members = number_of_members_impl<T>()
	The number of a default-constructible aggregate type's members. More...

template<conststr::cstr Name>
constexpr auto	basename_of = basename_of_impl<Name>()
	Base name of a full qualified name. More...

template<cptr Ptr>
constexpr auto	name_of_ptr = name_of_ptr_impl<Ptr>()
	Get the variable or class member name from its pointer. More...

template<typename T , std::size_t N>
constexpr auto	name_of = name_of_ptr<cptr_of_member<T, N>()>
	Name of N-th member of a default-constructible aggregate type `T`. More...

template<typename T , conststr::cstr Name>
constexpr size_t	index_of = index_of_impl<T, Name, 0>()
	Get the index of the member by its name. More...

Detailed Description

Compile-time reflection for aggregate types.

Typedef Documentation

◆ type_of

template<typename T , std::size_t N>

using reflect::type_of = typedef std::remove_cvref_t< std::tuple_element_t<N, decltype(to_tuple(fake_obj<T>))> >

Type of N-th member of a default-constructible aggregate type T.

Template Parameters

T	any default-constructible aggregate type
N	index of member

◆ type_of_member

template<typename T , conststr::cstr Name>

using reflect::type_of_member = typedef type_of<T, index_of<T, Name> >

Get the type of the member by its name.

This is just a simplified API of reflect::type_of<T, reflect::index_of<T, Name>>.

Template Parameters

T	any default-constructible aggregate type
Name	name of the member to search

Function Documentation

◆ basename_of_impl()

template<conststr::cstr Name>

consteval auto reflect::basename_of_impl ( )

Internal implementation of basename_of. get the Base name of a full qualified name.

Template Parameters

Name	string containing a name that may be quailfied

Returns: Base name of a full qualified name.

See also: basename_of

◆ cptr_of_member()

template<typename T , std::size_t N>

consteval auto reflect::cptr_of_member ( )

Get the pointer of the N-th member as a constexpr value.

Template Parameters

T	any type
N	index of the member

Returns: cptr wrapped pointer.

◆ index_of_impl()

template<typename T , conststr::cstr Name, std::size_t SrchIdx>
requires (number_of_members<T> > SrchIdx)

constexpr size_t reflect::index_of_impl ( )

constexpr

Internal implementation of index_of. Get the index of the member by its name.

Template Parameters

T	any default-constructible aggregate type
Name	name of the member to search
SrchIdx	for recursion only, keep it 0

Returns: Index of the member.

See also: index_of

◆ member_of() [1/2]

template<std::size_t N, typename T >

constexpr decltype(auto) reflect::member_of ( T && t )

constexpr

Get member reference of object t.

Please use decltype(auto) for deducing the return value type. For example:

struct S {
    int x;
    int y;
    int z;
};
S s = {};
decltype(auto) zref = reflect::member_of<2>(s);
zref = 10;
if (s.z == 10)
     std::cout << "Ok" << std::endl;

Template Parameters

N	index of member
T	DO NOT specify it, let it be automatically deduced

Parameters

t	object of type `T`

Returns: L-value reference if t is a l-value reference.; R-value reference if t is a r-value reference.

◆ member_of() [2/2]

template<conststr::cstr Name, typename T >
requires std::same_as<typename decltype(Name)::value_type, char>

constexpr decltype(auto) reflect::member_of ( T && t )

constexpr

Get member reference of object t via member's name.

Please use decltype(auto) for deducing the return value type. For example:

struct S {
    int x;
    int y;
    int z;
};
S s = {};
decltype(auto) zref = reflect::member_of<"z">(s);
zref = 10;
if (s.z == 10)
     std::cout << "Ok" << std::endl;

Template Parameters

Name	name of member
T	DO NOT specify it, let it be automatically deduced

Parameters

t	object of type `T`

Returns: L-value reference if t is a l-value reference.; R-value reference if t is a r-value reference.

◆ name_of_ptr_impl()

template<cptr Ptr>

consteval auto reflect::name_of_ptr_impl ( )

Internal implementation of name_of_ptr. Extract the real name from the output of pretty_name().

Template Parameters

Ptr	pointer to the the variable or class member you want to reflect.

Returns: Name of the variable or class member.

See also: name_of_ptr

◆ number_of_members_impl()

template<typename T , typename... Args>
requires (std::is_aggregate_v<std::remove_cvref_t<T>> && std::is_default_constructible_v<std::remove_cvref_t<T>>)

consteval std::size_t reflect::number_of_members_impl ( )

Internal implementation of number_of_members. Get The number of a default-constructible aggregate type's members.

Just call number_of_members_impl<T>() and keep the template pack Args empty. On how it works, it first tests whether T can be constructed with one parameter, if so, then tries to construct it with two parameters, and so on until T cannot be constructed with N parameters, then the number of members of T is N - 1.

Template Parameters

T	must be a default-constructible aggregate type
Args	for recursion only, keep it empty

Returns: The number of T's members.

See also: number_of_members

◆ pretty_name()

template<cptr Ptr>

consteval auto reflect::pretty_name ( )

Core function to get member name via compiler built-in macro.

Note: When using GCC, will return a string in the form of "consteval auto reflect::pretty_name() [with cptr<...auto...> Ptr = ...]".; When using clang, will return a string in the form of "auto reflect::pretty_name() [Ptr = ...]".; When using MSVC, will return a string in the form of "auto __cdecl reflect::pretty_name<...>(void)".

Template Parameters

Ptr	pointer to the the variable or member you want to reflect

Returns: A compile-time string containing the name of the variable or member and of type conststr::cstr.

See also: conststr::cstr; name_of()

◆ to_tuple()

template<class T , std::size_t N = number_of_members<T>>
requires (N <= 128)

constexpr decltype(auto) reflect::to_tuple ( T && t )

constexpr

Convert a value of type T to a tuple containing references to all its members.

Note: Only supports 128 members at most.

Template Parameters

T	any type.
N	number of `T`'s members, automatically calculated if `T` is a default constructible aggregate type. Otherwise, the caller needs to provide it.

Returns: Tuple containing references to all t's members.

Variable Documentation

◆ basename_of

template<conststr::cstr Name>

constexpr auto reflect::basename_of = basename_of_impl<Name>()

constexpr

Base name of a full qualified name.

For example, basename_of<"xxx::yyy::zzz->nnn"_cs> is "nnn"_cs.

Template Parameters

Name	Name the name that may be quailfied.

◆ fake_obj

template<typename T >

const T reflect::fake_obj

extern

An object of T that can be used in constant context without really construct it.

Template Parameters

T any type

◆ index_of

template<typename T , conststr::cstr Name>

constexpr size_t reflect::index_of = index_of_impl<T, Name, 0>()

constexpr

Get the index of the member by its name.

For example, reflect::index_of<S, "point"> if the type S has a member named point.

Template Parameters

T	any default-constructible aggregate type
Name	name of the member to search

Returns: Index of the member.

◆ name_of

template<typename T , std::size_t N>

constexpr auto reflect::name_of = name_of_ptr<cptr_of_member<T, N>()>

constexpr

Name of N-th member of a default-constructible aggregate type T.

Template Parameters

T	any default-constructible aggregate type
N	index of member

◆ name_of_ptr

template<cptr Ptr>

constexpr auto reflect::name_of_ptr = name_of_ptr_impl<Ptr>()

constexpr

Get the variable or class member name from its pointer.

Template Parameters

Ptr	pointer to the the variable or class member you want to reflect.

Note: MSVC currently fails to compile it when Ptr points to an array.

◆ number_of_members

template<typename T >

constexpr std::size_t reflect::number_of_members = number_of_members_impl<T>()

constexpr

The number of a default-constructible aggregate type's members.

Template Parameters

T	must be a default-constructible aggregate type

Classes

Typedefs

Functions

Variables

Detailed Description

Typedef Documentation

◆ type_of

◆ type_of_member

Function Documentation

◆ basename_of_impl()

◆ cptr_of_member()

◆ index_of_impl()

◆ member_of() [1/2]

◆ member_of() [2/2]

◆ name_of_ptr_impl()

◆ number_of_members_impl()

◆ pretty_name()

◆ to_tuple()

Variable Documentation

◆ basename_of

◆ fake_obj

◆ index_of

◆ name_of

◆ name_of_ptr

◆ number_of_members