From 0b39d67103025c4b15c424ff5e2ce4ce7399edd8 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <viz@meta.com>
Date: Mon, 1 Jan 2024 16:10:13 -0800
Subject: [PATCH] Remove detail::error_handler

---
 include/fmt/core.h   | 14 ++------------
 include/fmt/format.h |  4 +++-
 include/fmt/printf.h |  4 +---
 test/scan.h          |  4 ++--
 4 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index 94f3f22b..acbf292e 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -646,15 +646,6 @@ enum {
 
 // DEPRECATED!
 FMT_NORETURN FMT_API void throw_format_error(const char* message);
-
-struct error_handler {
-  constexpr error_handler() = default;
-
-  // This function is intentionally not constexpr to give a compile-time error.
-  FMT_NORETURN void on_error(const char* message) {
-    throw_format_error(message);
-  }
-};
 }  // namespace detail
 
 /** Throws ``format_error`` with a given message. */
@@ -1772,9 +1763,8 @@ template <typename OutputIt, typename Char> class basic_format_context {
   }
   auto args() const -> const format_args& { return args_; }
 
-  // DEPRECATED!
-  FMT_CONSTEXPR auto error_handler() -> detail::error_handler { return {}; }
-  void on_error(const char* message) { error_handler().on_error(message); }
+  // This function is intentionally not constexpr to give a compile-time error.
+  void on_error(const char* message) { throw_format_error(message); }
 
   // Returns an iterator to the beginning of the output range.
   FMT_CONSTEXPR auto out() -> iterator { return out_; }
diff --git a/include/fmt/format.h b/include/fmt/format.h
index 97f0e1fb..fbe344f2 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -4360,7 +4360,7 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
     return;
   }
 
-  struct format_handler : error_handler {
+  struct format_handler {
     basic_format_parse_context<Char> parse_context;
     buffer_context<Char> context;
 
@@ -4412,6 +4412,8 @@ void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
       context.advance_to(visit_format_arg(f, arg));
       return begin;
     }
+
+    void on_error(const char* message) { throw_format_error(message); }
   };
   detail::parse_format_string<false>(fmt, format_handler(out, fmt, args, loc));
 }
diff --git a/include/fmt/printf.h b/include/fmt/printf.h
index 07e81577..b70df5e7 100644
--- a/include/fmt/printf.h
+++ b/include/fmt/printf.h
@@ -53,9 +53,7 @@ template <typename Char> class basic_printf_context {
     return args_.get(id);
   }
 
-  FMT_CONSTEXPR void on_error(const char* message) {
-    detail::error_handler().on_error(message);
-  }
+  void on_error(const char* message) { throw_format_error(message); }
 };
 
 namespace detail {
diff --git a/test/scan.h b/test/scan.h
index a68c77c3..91351b00 100644
--- a/test/scan.h
+++ b/test/scan.h
@@ -573,7 +573,7 @@ struct arg_scanner {
   }
 };
 
-struct scan_handler : error_handler {
+struct scan_handler {
  private:
   scan_parse_context parse_ctx_;
   scan_context scan_ctx_;
@@ -626,7 +626,7 @@ struct scan_handler : error_handler {
     return begin;
   }
 
-  void on_error(const char* message) { error_handler::on_error(message); }
+  void on_error(const char* message) { throw_format_error(message); }
 };
 }  // namespace detail