Refactor StringStream Add methods

src/string-stream.h

Index: src/string-stream.h
diff --git a/src/string-stream.h b/src/string-stream.h
index 1c1d27a16beaa2404cddf6874e355a42318352b8..86697daf23c94ff925be135b341a4a222d18b6a0 100644
--- a/src/string-stream.h
+++ b/src/string-stream.h
@@ -5,8 +5,6 @@
 #ifndef V8_STRING_STREAM_H_
 #define V8_STRING_STREAM_H_
 
-#include <memory>
-
 #include "src/allocation.h"
 #include "src/handles.h"
 #include "src/vector.h"
@@ -59,32 +57,33 @@ class FixedStringAllocator final : public StringAllocator {
 
 class FmtElm final {
  public:
-  FmtElm(int value) : type_(INT) {  // NOLINT
-    data_.u_int_ = value;
-  }
-  explicit FmtElm(double value) : type_(DOUBLE) {
-    data_.u_double_ = value;
-  }
-  FmtElm(const char* value) : type_(C_STR) {  // NOLINT
-    data_.u_c_str_ = value;
-  }
-  FmtElm(const Vector<const uc16>& value) : type_(LC_STR) {  // NOLINT
-    data_.u_lc_str_ = &value;
-  }
-  FmtElm(Object* value) : type_(OBJ) {  // NOLINT
-    data_.u_obj_ = value;
-  }
-  FmtElm(Handle<Object> value) : type_(HANDLE) {  // NOLINT
-    data_.u_handle_ = value.location();
-  }
-  FmtElm(void* value) : type_(POINTER) {  // NOLINT
-    data_.u_pointer_ = value;
+#ifdef DEBUG

[titzer, 2016/11/17 17:00:38]

Could you do this macro stuff a different way? E.g. just having a macro to
initialize the debug-only {type_} field?

[Clemens Hammacher, 2016/11/17 18:40:01]

Did it, and it's much cleaner indeed. Even though more code.

+#define FMT_ELM_CONS(attr, ctype, type, field, data) \
+  attr FmtElm(ctype value) : type_(type) { data_.field = data; }
+#else
+#define FMT_ELM_CONS(attr, ctype, type, field, data) \
+  attr FmtElm(ctype value) { data_.field = data; }
+#endif
+  FMT_ELM_CONS(, int, INT, u_int_, value)
+  FMT_ELM_CONS(explicit, double, DOUBLE, u_double_, value)
+  FMT_ELM_CONS(, const char*, C_STR, u_c_str_, value)
+  FMT_ELM_CONS(, const Vector<const uc16>&, LC_STR, u_lc_str_, &value)
+  FMT_ELM_CONS(, Object*, OBJ, u_obj_, value)
+  FMT_ELM_CONS(, Handle<Object>, HANDLE, u_handle_, value.location())
+  FMT_ELM_CONS(, void*, POINTER, u_pointer_, value)
+#undef FMT_ELM_CONS
+
+  template <typename T>
+  static FmtElm From(T t) {
+    return t;
   }
 
  private:
   friend class StringStream;
+#ifdef DEBUG
   enum Type { INT, DOUBLE, C_STR, LC_STR, OBJ, HANDLE, POINTER };
   Type type_;
+#endif
   union {
     int u_int_;
     double u_double_;
@@ -114,22 +113,19 @@ class StringStream final {
   bool Put(String* str);
   bool Put(String* str, int start, int end);
   void Add(Vector<const char> format, Vector<FmtElm> elms);
-  void Add(const char* format);
-  void Add(Vector<const char> format);
-  void Add(const char* format, FmtElm arg0);
-  void Add(const char* format, FmtElm arg0, FmtElm arg1);
-  void Add(const char* format, FmtElm arg0, FmtElm arg1, FmtElm arg2);
-  void Add(const char* format,
-           FmtElm arg0,
-           FmtElm arg1,
-           FmtElm arg2,
-           FmtElm arg3);
-  void Add(const char* format,
-           FmtElm arg0,
-           FmtElm arg1,
-           FmtElm arg2,
-           FmtElm arg3,
-           FmtElm arg4);
+  void Add(const char* format) { Add(CStrVector(format)); }
+  void Add(Vector<const char> format) { Add(format, Vector<FmtElm>()); }
+
+  template <typename... Args>
+  void Add(const char* format, Args... args) {
+    Add<Args...>(CStrVector(format), args...);
+  }
+
+  template <typename... Args>
+  void Add(Vector<const char> format, Args... args) {
+    FmtElm elems[]{FmtElm::From(args)...};
+    Add(format, ArrayVector(elems));
+  }
 
   // Getting the message out.
   void OutputToFile(FILE* out);