A C++ template library for embedded applications
MIT licensed
Designed and
maintained by
John Wellbelove
Support the development
of the ETL
Type Lookup
Compile time mapping of id to type, type to id and type to type.
This file is generated from type_lookup_generator.h and can be created by running generate_type_lookup.bat.

For a less complex solution for simple id to type lookup, see etl::type_select.
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type_id_pair
Support structure for type_id_lookup.

etl::type_id_pair<typename T, size_t ID>
Defines:
type The type.
ID   The id associated with the type.
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type_type_pair
Support structure for type_type_lookup.

etl::type_type_pair<typename T1, typename T2>

Defines:
type1 The indexing type.
type2 The associated type.
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type_id_lookup
Creates a class for compile time id to type and type to id mappings.

etl::type_id_lookup<typename T1, ...>
The number of types that can be handled is determined by the generator.
Each template parameter is a type_id_pair.

The class contains two nested templates
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type_from_id
Gets the type from the id.
type_from_id<size_t ID>

Defines:
type The associated type.

C++14 and above
template <int ID>
using type_from_id_t = typename type_from_id<ID>::type;
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id_from_type
Gets the id from the type.
id_from_type<typename T>

Defines:
ID The associated id.

C++ 17 and above
template <typename T>
constexpr size_t id_from_type_v = id_from_type<T>::value;
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Static functions
Gets the id from the type.
template <typename T>
static unsigned int get_id_from_type(const T&)

template <typename T>
static unsigned int get_id_from_type()
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type_type_lookup
Creates a class for compile time type to type mapping.

etl::type_id_lookup<typename T1, ...>
The number of types that can be handled is determined by the generator.
Each template parameter is a type_id_pair.

The class contains one nested template.
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type_from_type
type_from_type<typename T>

Defines:
type The associated type.

C++14 and above
template <typename T>
using type_from_type_t = typename type_from_type<T>::type;
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Examples
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type_id_lookup
enum
{
  INT32  = 32,
  STRING = 1,
  UINT8  = 8,
  OTHER  = 0
};

typedef etl::type_id_pair<int32_t,     INT32>  TypeIdInt32;
typedef etl::type_id_pair<uint8_t,     UINT8>  TypeIdUint8;
typedef etl::type_id_pair<std::string, STRING> TypeIdString;

// Type from Id / Id from Type.
typedef etl::type_id_lookup<TypeIdInt32, TypeIdString, TypeIdUint8> TypeIdLookup;

// int32_t
typename TypeIdLookup::type_from_id_t<INT32>

// uint8_t
typename TypeIdLookup::type_from_id_t<UINT8>

// std::string
typename TypeIdLookup::type_from_id_t<STRING>

// Compile error
typename TypeIdLookup::type_from_id_t<OTHER>

// INT32
TypeIdLookup::id_from_type_v<int32_t>

// UINT8
TypeIdLookup::id_from_type_v<uint8_t>

// STRING
TypeIdLookup::id_from_type_v<std::string>

// Compile error
TypeIdLookup::id_from_type_v<double>
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type_type_lookup
// Get the next larger type.
typedef etl::type_type_pair<int16_t, int32_t>  TypeInt16;
typedef etl::type_type_pair<uint8_t, uint16_t> TypeUint8;
typedef etl::type_type_pair<float,   double>   TypeFloat;

// Type from Type.
etl::type_type_lookup<TypeInt16, TypeUint8, TypeFloat> TypeTypeLookup;

// int32_t
typename TypeTypeLookup::type_from_type_t<int16_t>

// uint16_t
typename TypeTypeLookup::type_from_type_t<uint8_t>

// double
typename TypeTypeLookup::type_from_type_t<float>

// Compile error
typename TypeTypeLookup::type_from_type_t<int32_t>
type_lookup.h