toml11/toml/types.hpp

202 lines
10 KiB
C++

// Copyright Toru Niina 2017.
// Distributed under the MIT License.
#ifndef TOML11_TYPES_HPP
#define TOML11_TYPES_HPP
#include "datetime.hpp"
#include "string.hpp"
#include "traits.hpp"
#include "comments.hpp"
#include <vector>
#include <unordered_map>
namespace toml
{
template<typename Comment, // discard/preserve_comment
template<typename ...> class Table, // map-like class
template<typename ...> class Array> // vector-like class
class basic_value;
using character = char;
using key = std::string;
using boolean = bool;
using integer = std::int64_t;
using floating = double; // "float" is a keyward, cannot use it here.
// the following stuffs are structs defined here, so aliases are not needed.
// - string
// - offset_datetime
// - offset_datetime
// - local_datetime
// - local_date
// - local_time
// default toml::value and default array/table. these are defined after defining
// basic_value itself.
// using value = basic_value<discard_comments, std::unordered_map, std::vector>;
// using array = typename value::array_type;
// using table = typename value::table_type;
enum class value_t : std::uint8_t
{
empty = 0,
boolean = 1,
integer = 2,
floating = 3,
string = 4,
offset_datetime = 5,
local_datetime = 6,
local_date = 7,
local_time = 8,
array = 9,
table = 10,
};
template<typename charT, typename traits>
inline std::basic_ostream<charT, traits>&
operator<<(std::basic_ostream<charT, traits>& os, value_t t)
{
switch(t)
{
case value_t::boolean : os << "boolean"; return os;
case value_t::integer : os << "integer"; return os;
case value_t::floating : os << "floating"; return os;
case value_t::string : os << "string"; return os;
case value_t::offset_datetime : os << "offset_datetime"; return os;
case value_t::local_datetime : os << "local_datetime"; return os;
case value_t::local_date : os << "local_date"; return os;
case value_t::local_time : os << "local_time"; return os;
case value_t::array : os << "array"; return os;
case value_t::table : os << "table"; return os;
case value_t::empty : os << "empty"; return os;
default : os << "unknown"; return os;
}
}
template<typename charT = char,
typename traits = std::char_traits<charT>,
typename alloc = std::allocator<charT>>
inline std::basic_string<charT, traits, alloc> stringize(value_t t)
{
std::basic_ostringstream<charT, traits, alloc> oss;
oss << t;
return oss.str();
}
namespace detail
{
// helper to define a type that represents a value_t value.
template<value_t V>
using value_t_constant = std::integral_constant<value_t, V>;
// meta-function that convertes from value_t to the exact toml type that corresponds to.
// It takes toml::basic_value type because array and table types depend on it.
template<value_t t, typename Value> struct enum_to_type {using type = void ;};
template<typename Value> struct enum_to_type<value_t::empty , Value>{using type = void ;};
template<typename Value> struct enum_to_type<value_t::boolean , Value>{using type = boolean ;};
template<typename Value> struct enum_to_type<value_t::integer , Value>{using type = integer ;};
template<typename Value> struct enum_to_type<value_t::floating , Value>{using type = floating ;};
template<typename Value> struct enum_to_type<value_t::string , Value>{using type = string ;};
template<typename Value> struct enum_to_type<value_t::offset_datetime, Value>{using type = offset_datetime ;};
template<typename Value> struct enum_to_type<value_t::local_datetime , Value>{using type = local_datetime ;};
template<typename Value> struct enum_to_type<value_t::local_date , Value>{using type = local_date ;};
template<typename Value> struct enum_to_type<value_t::local_time , Value>{using type = local_time ;};
template<typename Value> struct enum_to_type<value_t::array , Value>{using type = typename Value::array_type;};
template<typename Value> struct enum_to_type<value_t::table , Value>{using type = typename Value::table_type;};
// meta-function that converts from an exact toml type to the enum that corresponds to.
template<typename T, typename Value>
struct type_to_enum : std::conditional<
std::is_same<T, typename Value::array_type>::value, // if T == array_type,
value_t_constant<value_t::array>, // then value_t::array
typename std::conditional< // else...
std::is_same<T, typename Value::table_type>::value, // if T == table_type
value_t_constant<value_t::table>, // then value_t::table
value_t_constant<value_t::empty> // else value_t::empty
>::type
>::type {};
template<typename Value> struct type_to_enum<boolean , Value>: value_t_constant<value_t::boolean > {};
template<typename Value> struct type_to_enum<integer , Value>: value_t_constant<value_t::integer > {};
template<typename Value> struct type_to_enum<floating , Value>: value_t_constant<value_t::floating > {};
template<typename Value> struct type_to_enum<string , Value>: value_t_constant<value_t::string > {};
template<typename Value> struct type_to_enum<offset_datetime, Value>: value_t_constant<value_t::offset_datetime> {};
template<typename Value> struct type_to_enum<local_datetime , Value>: value_t_constant<value_t::local_datetime > {};
template<typename Value> struct type_to_enum<local_date , Value>: value_t_constant<value_t::local_date > {};
template<typename Value> struct type_to_enum<local_time , Value>: value_t_constant<value_t::local_time > {};
// meta-function that checks the type T is the same as one of the toml::* types.
template<typename T, typename Value>
struct is_exact_toml_type : disjunction<
std::is_same<T, boolean >,
std::is_same<T, integer >,
std::is_same<T, floating >,
std::is_same<T, string >,
std::is_same<T, offset_datetime>,
std::is_same<T, local_datetime >,
std::is_same<T, local_date >,
std::is_same<T, local_time >,
std::is_same<T, typename Value::array_type>,
std::is_same<T, typename Value::table_type>
>{};
template<typename T, typename V> struct is_exact_toml_type<T&, V> : is_exact_toml_type<T, V>{};
template<typename T, typename V> struct is_exact_toml_type<T const&, V> : is_exact_toml_type<T, V>{};
template<typename T, typename V> struct is_exact_toml_type<T volatile&, V> : is_exact_toml_type<T, V>{};
template<typename T, typename V> struct is_exact_toml_type<T const volatile&, V>: is_exact_toml_type<T, V>{};
// meta-function that check type T is convertible to toml::* types
template<typename T, typename Value>
struct is_convertible_to_toml_value : disjunction<
std::is_same<T, boolean>, // T is bool or
std::is_integral<T>, // T is an integer or
std::is_floating_point<T>, // T is a floating point or
std::is_same<T, std::string>, // T is std::string or
std::is_same<T, toml::string>, // T is toml::string or
is_string_literal<T>, // T is "string literal" or
std::is_same<T, toml::local_date>, // T is local_date or
std::is_same<T, toml::local_time>, // T is local_time or
std::is_same<T, toml::local_datetime>, // T is local_datetime or
std::is_same<T, toml::offset_datetime>, // T is offset_datetime or
std::is_same<T, std::chrono::system_clock::time_point>, // T is time_point or
is_chrono_duration<T>, // T is a duration or
std::is_same<T, typename Value::array_type>, // T is an array type or
std::is_same<T, typename Value::table_type> // T is an array type or
>{};
// meta-function that returns value_t that represent the convertible type
template<typename T, typename Value>
struct convertible_toml_type_of : std::conditional<
/* if */ is_exact_toml_type<T, Value>::value,
/* then */ value_t_constant<type_to_enum<T, Value>::value>,
/* else */ typename std::conditional<
// ----------------------------------------------------------------------
/* if */ std::is_integral<T>::value,
/* then */ value_t_constant<value_t::integer>,
/* else */ typename std::conditional<
// ----------------------------------------------------------------------
/* if */ std::is_floating_point<T>::value,
/* then */ value_t_constant<value_t::floating>,
/* else */ typename std::conditional<
// ----------------------------------------------------------------------
/* if */ std::is_same<T, std::string>::value,
/* then */ value_t_constant<value_t::string>,
/* else */ typename std::conditional<
// ----------------------------------------------------------------------
/* if */ is_string_literal<T>::value,
/* then */ value_t_constant<value_t::string>,
/* else */ typename std::conditional<
// ----------------------------------------------------------------------
/* if */ is_chrono_duration<T>::value,
/* then */ value_t_constant<value_t::local_time>,
/* else */ typename std::conditional<
// ----------------------------------------------------------------------
/* if */ std::is_same<T, std::chrono::system_clock::time_point>::value,
/* then */ value_t_constant<value_t::offset_datetime>,
/* else */ value_t_constant<value_t::empty>
// ----------------------------------------------------------------------
>::type>::type>::type>::type>::type>::type>::type {};
} // detail
} // toml
#endif// TOML11_TYPES_H