Support signed char and unsigned char strings

format.h

@@ -651,6 +651,8 @@ struct Value {
     long double long_double_value;
     const void *pointer;
     StringValue<char> string;
+    StringValue<signed char> sstring;
+    StringValue<unsigned char> ustring;
     StringValue<wchar_t> wstring;
     CustomValue custom;
   };
@@ -758,6 +760,8 @@ public:
 
   FMT_MAKE_VALUE(char *, string.value, CSTRING)
   FMT_MAKE_VALUE(const char *, string.value, CSTRING)
+  FMT_MAKE_VALUE(const signed char *, sstring.value, CSTRING)
+  FMT_MAKE_VALUE(const unsigned char *, ustring.value, CSTRING)
   FMT_MAKE_STR_VALUE(const std::string &, STRING)
   FMT_MAKE_STR_VALUE(StringRef, STRING)
 

test/format-test.cc

@@ -1170,6 +1170,20 @@ TEST(FormatterTest, FormatCString) {
       FormatError, "string pointer is null");
 }
 
+TEST(FormatterTest, FormatSCharString) {
+  signed char str[] = "test";
+  EXPECT_EQ("test", format("{0:s}", str));
+  const signed char *const_str = str;
+  EXPECT_EQ("test", format("{0:s}", const_str));
+}
+
+TEST(FormatterTest, FormatUCharString) {
+  unsigned char str[] = "test";
+  EXPECT_EQ("test", format("{0:s}", str));
+  const unsigned char *const_str = str;
+  EXPECT_EQ("test", format("{0:s}", const_str));
+}
+
 TEST(FormatterTest, FormatPointer) {
   check_unknown_types(reinterpret_cast<void*>(0x1234), "p", "pointer");
   EXPECT_EQ("0x0", format("{0}", reinterpret_cast<void*>(0)));