Fix warnings caused by usage of deprecated functionality

include/fmt/core.h

@@ -1076,7 +1076,11 @@ class context_base {
 
  public:
   basic_parse_context<char_type>& parse_context() { return parse_context_; }
-  FMT_DEPRECATED basic_format_args<Context> args() const { return args_; }
+
+  // basic_format_context::arg() depends on this
+  // Cannot be marked as deprecated without causing warnings
+  /*FMT_DEPRECATED*/ basic_format_args<Context> args() const { return args_; }
+
   basic_format_arg<Context> arg(unsigned id) const { return args_.get(id); }
 
   internal::error_handler error_handler() {

test/format-impl-test.cc

@@ -116,9 +116,10 @@ template <typename T> struct ValueExtractor : fmt::internal::function<T> {
 TEST(FormatTest, ArgConverter) {
   long long value = std::numeric_limits<long long>::max();
   auto arg = fmt::internal::make_arg<fmt::format_context>(value);
-  visit(fmt::internal::arg_converter<long long, fmt::format_context>(arg, 'd'),
-        arg);
-  EXPECT_EQ(value, visit(ValueExtractor<long long>(), arg));
+  fmt::visit_format_arg(
+      fmt::internal::arg_converter<long long, fmt::format_context>(arg, 'd'),
+      arg);
+  EXPECT_EQ(value, fmt::visit_format_arg(ValueExtractor<long long>(), arg));
 }
 
 TEST(FormatTest, FormatNegativeNaN) {

test/format-test.cc

@@ -1720,13 +1720,32 @@ TEST(FormatIntTest, FormatInt) {
             fmt::format_int(std::numeric_limits<int64_t>::max()).str());
 }
 
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif
+
+#if FMT_MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4996) // Using a deprecated function
+#endif
+
 template <typename T> std::string format_decimal(T value) {
   char buffer[10];
   char* ptr = buffer;
-  fmt::format_decimal(ptr, value);
+  // TODO: Replace with safer, non-deprecated overload
+  fmt::format_decimal(ptr, value); 
   return std::string(buffer, ptr);
 }
 
+#if FMT_MSC_VER
+#pragma warning(pop)
+#endif
+
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
+
 TEST(FormatIntTest, FormatDec) {
   EXPECT_EQ("-42", format_decimal(static_cast<signed char>(-42)));
   EXPECT_EQ("-42", format_decimal(static_cast<short>(-42)));

test/ostream-test.cc

@@ -59,7 +59,8 @@ TEST(OStreamTest, CustomArg) {
   fmt::format_context ctx(std::back_inserter(base), "", fmt::format_args());
   fmt::format_specs spec;
   test_arg_formatter af(ctx, spec);
-  visit(af, fmt::internal::make_arg<fmt::format_context>(TestEnum()));
+  fmt::visit_format_arg(
+      af, fmt::internal::make_arg<fmt::format_context>(TestEnum()));
   EXPECT_EQ("TestEnum", std::string(buffer.data(), buffer.size()));
 }
 
@@ -178,8 +179,7 @@ template <typename Output> Output& operator<<(Output& out, ABC) {
 }
 }  // namespace fmt_test
 
-template <typename T>
-struct TestTemplate {};
+template <typename T> struct TestTemplate {};
 
 template <typename T>
 std::ostream& operator<<(std::ostream& os, TestTemplate<T>) {
@@ -187,14 +187,13 @@ std::ostream& operator<<(std::ostream& os, TestTemplate<T>) {
 }
 
 namespace fmt {
-template <typename T>
-struct formatter<TestTemplate<T>> : formatter<int> {
+template <typename T> struct formatter<TestTemplate<T>> : formatter<int> {
   template <typename FormatContext>
   typename FormatContext::iterator format(TestTemplate<T>, FormatContext& ctx) {
     return formatter<int>::format(2, ctx);
   }
 };
-}
+}  // namespace fmt
 
 #if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 407
 TEST(OStreamTest, Template) {