From 61dfa4a2dce2f8a328f7ec3d5c3d1e735b8049d8 Mon Sep 17 00:00:00 2001
From: ToruNiina <niina.toru.68u@gmail.com>
Date: Fri, 15 Mar 2019 12:38:37 +0900
Subject: [PATCH] feat: format any number of values into an err msg

```cpp
toml::format_error("[error] message", v1, "v1", v2, "v2", ...);
```
---
 toml/value.hpp | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/toml/value.hpp b/toml/value.hpp
index 27c2d8a..a866b04 100644
--- a/toml/value.hpp
+++ b/toml/value.hpp
@@ -794,24 +794,38 @@ inline bool operator>=(const toml::value& lhs, const toml::value& rhs)
     return !(lhs < rhs);
 }
 
-inline std::string format_error(const std::string& err_msg,
-        const toml::value& v, const std::string& comment,
-        std::vector<std::string> hints = {})
+namespace detail
 {
-    return detail::format_underline(err_msg, {
-            {std::addressof(detail::get_region(v)), comment}
-        }, std::move(hints));
+inline std::string format_error_impl(const std::string& err_msg,
+        std::vector<std::pair<region_base const*, std::string>> val,
+        std::vector<std::string> hints)
+{
+    return format_underline(err_msg, std::move(val), std::move(hints));
+}
+inline std::string format_error_impl(const std::string& err_msg,
+        std::vector<std::pair<region_base const*, std::string>> val)
+{
+    return format_underline(err_msg, std::move(val));
 }
 
-inline std::string format_error(const std::string& err_msg,
-        const toml::value& v1, const std::string& comment1,
-        const toml::value& v2, const std::string& comment2,
-        std::vector<std::string> hints = {})
+template<typename ... Ts>
+std::string format_error_impl(const std::string& err_msg,
+        std::vector<std::pair<region_base const*, std::string>> val,
+        const toml::value& v, const std::string& comment,
+        Ts&& ... args)
 {
-    return detail::format_underline(err_msg, {
-            {std::addressof(detail::get_region(v1)), comment1},
-            {std::addressof(detail::get_region(v2)), comment2}
-        }, std::move(hints));
+    val.push_back(std::make_pair(std::addressof(get_region(v)), comment));
+    return format_error_impl(err_msg, std::move(val), std::forward<Ts>(args)...);
+}
+} // detail
+
+template<typename ... Ts>
+std::string format_error(const std::string& err_msg, Ts&& ... args)
+{
+    std::vector<std::pair<detail::region_base const*, std::string>> val;
+    val.reserve(sizeof...(args) / 2);
+    return detail::format_error_impl(err_msg, std::move(val),
+                                     std::forward<Ts>(args)...);
 }
 
 template<typename Visitor>