diff --git a/include/flatbuffers/util.h b/include/flatbuffers/util.h
index 2aafa48..2e0ce73 100644
--- a/include/flatbuffers/util.h
+++ b/include/flatbuffers/util.h
@@ -17,19 +17,20 @@
 #ifndef FLATBUFFERS_UTIL_H_
 #define FLATBUFFERS_UTIL_H_
 
+#include <ctype.h>
 #include <errno.h>
 
 #include "flatbuffers/base.h"
 #include "flatbuffers/stl_emulation.h"
 
 #ifndef FLATBUFFERS_PREFER_PRINTF
+#  include <iomanip>
 #  include <sstream>
 #else  // FLATBUFFERS_PREFER_PRINTF
 #  include <float.h>
 #  include <stdio.h>
 #endif  // FLATBUFFERS_PREFER_PRINTF
 
-#include <iomanip>
 #include <string>
 
 namespace flatbuffers {
@@ -51,6 +52,9 @@
   return check_ascii_range(c & 0xDF, 'a' & 0xDF, 'z' & 0xDF);
 }
 
+// Check for uppercase alpha
+inline bool is_alpha_upper(char c) { return check_ascii_range(c, 'A', 'Z'); }
+
 // Check (case-insensitive) that `c` is equal to alpha.
 inline bool is_alpha_char(char c, char alpha) {
   FLATBUFFERS_ASSERT(is_alpha(alpha));
@@ -91,7 +95,7 @@
   // Count a single 0 left of the dot for fractional numbers
   if (-1 < t && t < 1) digit_count++;
   // Count digits until fractional part
-  T eps = std::numeric_limits<float>::epsilon();
+  T eps = std::numeric_limits<T>::epsilon();
   while (t <= (-1 + eps) || (1 - eps) <= t) {
     t /= 10;
     digit_count++;
@@ -142,20 +146,6 @@
 template<> inline std::string NumToString<char>(char t) {
   return NumToString(static_cast<int>(t));
 }
-#if defined(FLATBUFFERS_CPP98_STL)
-template<> inline std::string NumToString<long long>(long long t) {
-  char buf[21];  // (log((1 << 63) - 1) / log(10)) + 2
-  snprintf(buf, sizeof(buf), "%lld", t);
-  return std::string(buf);
-}
-
-template<>
-inline std::string NumToString<unsigned long long>(unsigned long long t) {
-  char buf[22];  // (log((1 << 63) - 1) / log(10)) + 1
-  snprintf(buf, sizeof(buf), "%llu", t);
-  return std::string(buf);
-}
-#endif  // defined(FLATBUFFERS_CPP98_STL)
 
 // Special versions for floats/doubles.
 template<typename T> std::string FloatToString(T t, int precision) {
@@ -332,6 +322,9 @@
 // - If the converted value falls out of range of corresponding return type, a
 // range error occurs. In this case value MAX(T)/MIN(T) is returned.
 template<typename T> inline bool StringToNumber(const char *s, T *val) {
+  // Assert on `unsigned long` and `signed long` on LP64.
+  // If it is necessary, it could be solved with flatbuffers::enable_if<B,T>.
+  static_assert(sizeof(T) < sizeof(int64_t), "unexpected type T");
   FLATBUFFERS_ASSERT(s && val);
   int64_t i64;
   // The errno check isn't needed, will return MAX/MIN on overflow.
@@ -462,6 +455,7 @@
 
 // Replaces any '\\' separators with '/'
 std::string PosixPath(const char *path);
+std::string PosixPath(const std::string &path);
 
 // This function ensure a directory exists, by recursively
 // creating dirs for any parts of the path that don't exist yet.
@@ -471,6 +465,10 @@
 // Returns the input path if the absolute path couldn't be resolved.
 std::string AbsolutePath(const std::string &filepath);
 
+// Returns files relative to the --project_root path, prefixed with `//`.
+std::string RelativeToRootPath(const std::string &project,
+                               const std::string &filepath);
+
 // To and from UTF-8 unicode conversion functions
 
 // Convert a unicode code point into a UTF-8 representation by appending it
@@ -687,6 +685,30 @@
 // MSVC specific: Send all assert reports to STDOUT to prevent CI hangs.
 void SetupDefaultCRTReportMode();
 
+enum class Case {
+  kUnknown = 0,
+  // TheQuickBrownFox
+  kUpperCamel = 1,
+  // theQuickBrownFox
+  kLowerCamel = 2,
+  // the_quick_brown_fox
+  kSnake = 3,
+  // THE_QUICK_BROWN_FOX
+  kScreamingSnake = 4,
+  // THEQUICKBROWNFOX
+  kAllUpper = 5,
+  // thequickbrownfox
+  kAllLower = 6,
+  // the-quick-brown-fox
+  kDasher = 7,
+  // THEQuiCKBr_ownFox (or whatever you want, we won't change it)
+  kKeep = 8,
+};
+
+// Convert the `input` string of case `input_case` to the specified `output_case`.
+std::string ConvertCase(const std::string &input, Case output_case,
+                    Case input_case = Case::kSnake);
+
 }  // namespace flatbuffers
 
 #endif  // FLATBUFFERS_UTIL_H_