Minimal C++17 header-only Compile-Time Reflection Library in ~300 LOC.
DESCRIBE() + MEMBER() macros allow to create compile-time descriptions for later use in deserialization, introspection, RPC, meta-objects system and many more
It is simple in API and implementation. Compilation is very fast, considering a very small amount of templates. Any impact on compilation is lazy (at the place of use)
- Compile time introspection of classes
- Multiple/Single Inheritance support
- Enumerations support
- Templates support
- Compile time attributes
- Aliases
- Boost.Json: Basic integration example
- nlohmann_json: Attributes usage example
- LUA Bindings: Auto-generate bindings with LUA
- RPC: Full-fledged JSON-RPC library with Deserialization based on describe
struct Data {
int a;
int b;
void method() {}
};
DESCRIBE("Data", Data) {
MEMBER("renamed", &_::a);
MEMBER("b", &_::b);
MEMBER("method", &_::method);
}
template<typename T>
void print_fields(const T& d) {
constexpr auto desc = describe::Get<T>();
std::cout << desc.name << ": ";
desc.for_each([&](auto f){
if constexpr (f.is_field) {
std::cout << f.name << " -> " << f.get(d) << ", ";
}
if constexpr (f.is_method) {
std::cout << f.name << "()" << ", ";
}
});
std::cout << std::endl;
}
print_fields(Data{1, 2}); // Data: renamed -> 1, b -> 2, method(),struct Parent {
std::string a;
std::string b;
};
DESCRIBE("Parent", Parent) {
MEMBER("a", &_::a);
MEMBER("b", &_::b);
}
struct Child : Parent {
std::string c;
};
DESCRIBE("Child", Child) {
PARENT(Parent); // may be repeated with multiple bases
MEMBER("c", &_::c);
}enum Mode {
read,
write,
read_write,
};
DESCRIBE("Mode", Mode) {
MEMBER("r", read);
MEMBER("read", read);
MEMBER("w", write);
MEMBER("write", write);
MEMBER("rw", read_write);
MEMBER("read_write", read_write);
}
constexpr Mode convert(std::string_view name) {
Mode res{};
if (describe::name_to_enum(name, res)) {
return res;
} else {
throw "Invalid";
}
}
constexpr auto mode1 = convert("rw");
constexpr auto mode2 = convert("read_write");
static_assert(mode1 == mode2);
static_assert(mode1 == Mode::read_write);