109 lines
2.9 KiB
C++
109 lines
2.9 KiB
C++
#ifndef RJP_DISPATCH_HPP
|
|
#define RJP_DISPATCH_HPP
|
|
|
|
#include "rjp_internal.hpp"
|
|
#include <type_traits> //is_same, true_type, false_type
|
|
#include <utility> //forward
|
|
|
|
namespace rjp{
|
|
|
|
namespace detail{
|
|
template<RJP_data_type T>
|
|
struct to_value_type;
|
|
|
|
template<>
|
|
struct to_value_type<rjp_json_object>{
|
|
using type = rjp::object;
|
|
};
|
|
template<>
|
|
struct to_value_type<rjp_json_string>{
|
|
using type = rjp::string_val;
|
|
};
|
|
template<>
|
|
struct to_value_type<rjp_json_integer>{
|
|
using type = rjp::integer;
|
|
};
|
|
template<>
|
|
struct to_value_type<rjp_json_dfloat>{
|
|
using type = rjp::dfloat;
|
|
};
|
|
template<>
|
|
struct to_value_type<rjp_json_boolean>{
|
|
using type = rjp::boolean;
|
|
};
|
|
template<>
|
|
struct to_value_type<rjp_json_array>{
|
|
using type = rjp::array;
|
|
};
|
|
template<>
|
|
struct to_value_type<rjp_json_null>{
|
|
using type = rjp::null;
|
|
};
|
|
template<RJP_data_type T>
|
|
using to_value_type_t = typename to_value_type<T>::type;
|
|
|
|
template<RJP_data_type T>
|
|
struct next_data_type;
|
|
template<>
|
|
struct next_data_type<rjp_json_object>{
|
|
static constexpr RJP_data_type value = rjp_json_string;
|
|
};
|
|
template<>
|
|
struct next_data_type<rjp_json_string>{
|
|
static constexpr RJP_data_type value = rjp_json_integer;
|
|
};
|
|
template<>
|
|
struct next_data_type<rjp_json_integer>{
|
|
static constexpr RJP_data_type value = rjp_json_dfloat;
|
|
};
|
|
template<>
|
|
struct next_data_type<rjp_json_dfloat>{
|
|
static constexpr RJP_data_type value = rjp_json_boolean;
|
|
};
|
|
template<>
|
|
struct next_data_type<rjp_json_boolean>{
|
|
static constexpr RJP_data_type value = rjp_json_array;
|
|
};
|
|
template<>
|
|
struct next_data_type<rjp_json_array>{
|
|
static constexpr RJP_data_type value = rjp_json_null;
|
|
};
|
|
|
|
template<RJP_data_type T>
|
|
struct has_next_data_type_helper{
|
|
template<class U, bool = (sizeof(U) == sizeof(U))>
|
|
static std::true_type check(U*);
|
|
static std::false_type check(...);
|
|
|
|
static constexpr bool value = std::is_same<std::true_type,decltype(check((next_data_type<T>*)0))>::value;
|
|
};
|
|
template<RJP_data_type T>
|
|
struct has_next_data_type{
|
|
static constexpr bool value = has_next_data_type_helper<T>::value;
|
|
};
|
|
template<class Func, class Val, RJP_data_type T>
|
|
decltype(auto) dispatch_helper(Func&& fun, Val&& v){
|
|
if(v.type() == T){
|
|
return std::forward<Func>(fun)(static_cast<detail::to_value_type_t<T>>(std::forward<Val>(v)));
|
|
}
|
|
if constexpr(detail::has_next_data_type<T>::value){
|
|
return dispatch_helper<Func,Val,detail::next_data_type<T>::value>(std::forward<Func>(fun), std::forward<Val>(v));
|
|
}
|
|
}
|
|
}
|
|
template<class Func, class Val>
|
|
decltype(auto) dispatch(Func&& fun, Val&& v){
|
|
return detail::dispatch_helper<Func,Val,rjp_json_object>(std::forward<Func>(fun), std::forward<Val>(v));
|
|
}
|
|
template<class... Ts>
|
|
struct dispatcher : public Ts...
|
|
{
|
|
using Ts::operator()...;
|
|
};
|
|
|
|
template<class... Ts>
|
|
dispatcher(Ts&&...) -> dispatcher<Ts...>;
|
|
}
|
|
|
|
#endif
|