From 8efb305e8ba3b585d44eba31cda35551a9f5a52e Mon Sep 17 00:00:00 2001
From: ToruNiina <niina.toru.68u@gmail.com>
Date: Fri, 28 Jun 2024 00:09:29 +0900
Subject: [PATCH] feat: add try_from to return result<T, E>

---
 include/toml11/from.hpp   | 13 ++++++++++++-
 include/toml11/traits.hpp |  9 +++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/include/toml11/from.hpp b/include/toml11/from.hpp
index d2e0e13..280cc40 100644
--- a/include/toml11/from.hpp
+++ b/include/toml11/from.hpp
@@ -7,7 +7,18 @@ namespace toml
 template<typename T>
 struct from;
 // {
-//     static T from_toml(const toml::value& v)
+//     template<typename TC>
+//     static T from_toml(const toml::basic_value<TC>& v)
+//     {
+//         // User-defined conversions ...
+//     }
+// };
+
+template<typename T>
+struct try_from;
+// {
+//     template<typename TC>
+//     static result<T, error_info> try_from_toml(const toml::basic_value<TC>& v) noexcept
 //     {
 //         // User-defined conversions ...
 //     }
diff --git a/include/toml11/traits.hpp b/include/toml11/traits.hpp
index 0a0fa79..946f760 100644
--- a/include/toml11/traits.hpp
+++ b/include/toml11/traits.hpp
@@ -90,6 +90,13 @@ struct has_specialized_from_impl
     template<typename T, std::size_t S = sizeof(::toml::from<T>)>
     static std::true_type check(::toml::from<T>*);
 };
+struct has_specialized_try_from_impl
+{
+    template<typename T>
+    static std::false_type check(...);
+    template<typename T, std::size_t S = sizeof(::toml::try_from<T>)>
+    static std::true_type check(::toml::try_from<T>*);
+};
 struct has_specialized_into_impl
 {
     template<typename T>
@@ -130,6 +137,8 @@ template<typename T>
 struct has_specialized_from: decltype(has_specialized_from_impl::check<T>(nullptr)){};
 template<typename T>
 struct has_specialized_into: decltype(has_specialized_into_impl::check<T>(nullptr)){};
+template<typename T>
+struct has_specialized_try_from: decltype(has_specialized_try_from_impl::check<T>(nullptr)){};
 
 #ifdef __INTEL_COMPILER
 #undef decltype