Revert "Support for comma-separated arguments. Fixes #2"

This reverts commit baf457f.

dbg.h

@@ -163,37 +163,30 @@ prettyPrint(std::ostream &stream, Container const &value) {
   return true;
 }
 
-template <typename ...Args>
-class DebugOutput_impl {
+class DebugOutput {
  public:
-  DebugOutput_impl(const char* filename, int line, const char* function_name, Args && ... args)
+  DebugOutput(const char* filename, int line, const char* function_name, const char* argument)
       : m_stderr_is_a_tty(isatty(fileno(stderr))),
         m_filename(filename),
         m_line(line),
         m_function_name(function_name),
-        m_arguments{args...} {}
-
-  template <typename... Brgs>
-  void print(Brgs&&... brgs) {
-    size_t i = 0;
-    // expander trick to emulate C++17 fold expression
-    using expander = int[];
-    (void)expander{0, (void(printValue(std::forward<Brgs>(brgs), i++)), 0)...};
-  }
+        m_argument(argument) {}
 
   template <typename T>
-  void printValue(T&& value, size_t i) const {
+  T&& print(T&& value) const {
     const T& ref = value;
     std::stringstream stream_value;
     const bool print_expression = prettyPrint(stream_value, ref);
 
     std::cerr << ansi(ANSI_WARNING_COLOR) << "[DEBUG " << m_filename << ":"
               << m_line << " (" << m_function_name << ")] ";
     if (print_expression) {
-      std::cerr << ansi(ANSI_RESET) <<  m_arguments[i] << ansi(ANSI_BOLD) << " = ";
+      std::cerr << ansi(ANSI_RESET) << m_argument << ansi(ANSI_BOLD) << " = ";
     }
     std::cerr << ansi(ANSI_RESET)
               << ansi(ANSI_VALUE_COLOR) << stream_value.str() << ansi(ANSI_RESET) << std::endl;
+
+    return std::forward<T>(value);
   }
 
  private:
@@ -210,7 +203,7 @@ class DebugOutput_impl {
   const std::string m_filename;
   const int m_line;
   const std::string m_function_name;
-  const char * m_arguments[sizeof...(Args)];
+  const std::string m_argument;
 
   static constexpr const char* const ANSI_EMPTY = "";
   static constexpr const char* const ANSI_WARNING_COLOR = "\x1b[33;01m";
@@ -219,46 +212,10 @@ class DebugOutput_impl {
   static constexpr const char* const ANSI_RESET = "\x1b[0m";
 };
 
-template <typename... Args>
-DebugOutput_impl<Args...> DebugOutput(const char* filename,
-                                      int line,
-                                      const char* function_name,
-                                      Args&&... args) {
-  return DebugOutput_impl<Args...>{filename, line, function_name,
-                                   std::forward<Args>(args)...};
-}
-
 }  // namespace dbg_macro
 
-#define STRINGIFY(s) _STRINGIFY(s)
-#define _STRINGIFY(s) #s
-
-#define FOREACH_1(fn, x) fn(x)
-#define FOREACH_2(fn, x, ...) fn(x), FOREACH_1(fn, __VA_ARGS__)
-#define FOREACH_3(fn, x, ...) fn(x), FOREACH_2(fn, __VA_ARGS__)
-#define FOREACH_4(fn, x, ...) fn(x), FOREACH_3(fn, __VA_ARGS__)
-#define FOREACH_5(fn, x, ...) fn(x), FOREACH_4(fn, __VA_ARGS__)
-#define FOREACH_6(fn, x, ...) fn(x), FOREACH_5(fn, __VA_ARGS__)
-#define FOREACH_7(fn, x, ...) fn(x), FOREACH_6(fn, __VA_ARGS__)
-
-#define FOREACH_N(_1, _2, _3, _4, _5, _6, _7, N, ...) N
-
-// clang-format off
-#define FOREACH(fn, ...) \
-  FOREACH_N(__VA_ARGS__, \
-          FOREACH_7,     \
-          FOREACH_6,     \
-          FOREACH_5,     \
-          FOREACH_4,     \
-          FOREACH_3,     \
-          FOREACH_2,     \
-          FOREACH_1)     \
-  (fn, __VA_ARGS__)
-// clang-format on
-
-#define dbg(...)                                          \
-  dbg_macro::DebugOutput(__FILE__, __LINE__, __func__,    \
-                         FOREACH(STRINGIFY, __VA_ARGS__)) \
-      .print(__VA_ARGS__)
+// We use a variadic macro to support commas inside expressions (e.g. initializer lists):
+#define dbg(...) \
+  dbg_macro::DebugOutput(__FILE__, __LINE__, __func__, #__VA_ARGS__).print((__VA_ARGS__))
 
 #endif  // DBG_MACRO_DBG_H