From ffe414cad13d66c7dcefa412d41f377c9635b80c Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Sun, 22 Jul 2018 15:30:51 -0700
Subject: [PATCH] Add compile-time format string checks to format_to (#783)

---
 include/fmt/format.h | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/include/fmt/format.h b/include/fmt/format.h
index d827306a..fcb13a25 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -3524,19 +3524,16 @@ inline wformat_context::iterator vformat_to(
   return vformat_to<arg_formatter<range>>(buf, format_str, args);
 }
 
-template <typename... Args, std::size_t SIZE = inline_buffer_size>
+template <typename String, typename... Args,
+          std::size_t SIZE = inline_buffer_size>
 inline format_context::iterator format_to(
-    basic_memory_buffer<char, SIZE> &buf, string_view format_str,
+    basic_memory_buffer<char, SIZE> &buf, const String &format_str,
     const Args & ... args) {
-  return vformat_to(buf, format_str, make_format_args(args...));
-}
-
-template <typename... Args, std::size_t SIZE = inline_buffer_size>
-inline wformat_context::iterator format_to(
-    basic_memory_buffer<wchar_t, SIZE> &buf, wstring_view format_str,
-    const Args & ... args) {
-  return vformat_to(buf, format_str,
-                    make_format_args<wformat_context>(args...));
+  internal::check_format_string<Args...>(format_str);
+  typedef typename internal::format_string_traits<String>::char_type char_t;
+  return vformat_to(
+        buf, basic_string_view<char_t>(format_str),
+        make_format_args<typename buffer_context<char_t>::type>(args...));
 }
 
 template <typename OutputIt, typename Char = char>