#include "include/meta_enum.hpp" #include <iostream> //helpers constexpr int sum(int a, int b, int c) { return a + b + c; } //can be used for global or nested enums or enum classes //first arg is the name of the enum. second is the underlying type. The rest are enum members. meta_enum(Global, int, GlobalA, GlobalB = 3, GlobalC, GlobalD = 100); meta_enum_class(GlobalClass, uint8_t, GlobalClassA, GlobalClassB = 3, GlobalClassC); struct Nester { meta_enum(Nested, int, NestedA, NestedB = 3); meta_enum_class(NestedClass, uint8_t, NestedClassA = 3, NestedClassB = 1 >> 3); }; //also works with very complexly defined enum entries meta_enum(Complex, int, First, Second= sum(1, {(2, ")h(),,\"ej", 1)}, 4 >> 2), Third = 4, Fourth); //static assertions to verify that the complexly defined enum is parsed correctly static_assert(Complex_meta.members.size() == 4); static_assert(Complex_meta.members[0].string == "First"); static_assert(Complex_meta.members[1].string == " Second= sum(1, {(2, \")h(),,\\\"ej\", 1)}, 4 >> 2)"); static_assert(Complex_meta.members[2].string == " Third = 4"); static_assert(Complex_meta.members[3].string == " Fourth"); static_assert(Complex_meta.members[0].name == "First"); static_assert(Complex_meta.members[1].name == "Second"); static_assert(Complex_meta.members[2].name == "Third"); static_assert(Complex_meta.members[3].name == "Fourth"); static_assert(Complex_meta.members[0].value == 0); static_assert(Complex_meta.members[1].value == 3); static_assert(Complex_meta.members[2].value == 4); static_assert(Complex_meta.members[3].value == 5); static_assert(Complex_meta.members[0].index == 0); static_assert(Complex_meta.members[1].index == 1); static_assert(Complex_meta.members[2].index == 2); static_assert(Complex_meta.members[3].index == 3); int main() { //enum meta objects are accessible with the _meta object //meta object has 'string' for full enum declaration string and 'members' for an array of all members //each member is an object of type MetaEnumMember std::cout << "global string: " << Global_meta.string << "\n"; std::cout << "global count: " << Global_meta.members.size() << "\n"; std::cout << "global class string: " << GlobalClass_meta.string << "\n"; std::cout << "global class count: " << GlobalClass_meta.members.size() << "\n"; std::cout << "nested string: " << Nester::Nested_meta.string << "\n"; std::cout << "nested count: " << Nester::Nested_meta.members.size() << "\n"; std::cout << "nested class string: " << Nester::NestedClass_meta.string << "\n"; std::cout << "nested class count: " << Nester::NestedClass_meta.members.size() << "\n\n"; //enum member objects have the following members: std::cout << "global members:\n"; for(const auto& enumMember : Global_meta.members) { using UnderlyingType = decltype(Global_meta)::UnderlyingType; std::cout << "index=" << enumMember.index << ", name='" << enumMember.name << "', value: " << static_cast<UnderlyingType>(enumMember.value) << ", string='" << enumMember.string << "'\n"; } std::cout << "\n"; //helper functions are defined for convenience that operate on the _meta datastructure //value_to_string gets the name of an enum value and '__INVALID_ENUM_VAL__' on failure std::cout << "value_to_string: input=" << Nester::NestedB << " output='" << Nester::Nested_value_to_string(Nester::NestedB) << "'\n"; //these are different ways to access the meta enum member objects. they return an std::optional which will be empty on bad input std::cout << "meta_from_name accesses through name. input=" << "NestedClassA" << " found_index=" << Nester::NestedClass_meta_from_name("NestedClassA")->index << "\n"; std::cout << "meta_from_value accesses through enum value. input=" << Nester::NestedB << " found_index=" << Nester::Nested_meta_from_value(Nester::NestedB)->index << "\n"; std::cout << "meta_from_index accesses through index. input=" << 2 << " found_name='" << GlobalClass_meta_from_index(2)->name << "'\n"; } |