rfc : -Wshorten-64-to-32 warnings in folly liger dependencies

[folly.git] / folly / String-inl.h

diff --git a/folly/String-inl.h b/folly/String-inl.h
index e680473b6b229c297efbd8d027e5aeb567388144..27b02a614f96f4fffe949cd6ccdfc6bc19a279c0 100644 (file)
--- a/folly/String-inl.h
+++ b/folly/String-inl.h
@@ -320,9 +320,9 @@ void internalSplit(DelimT delim, StringPiece sp, OutputIterator out,
       ignoreEmpty);
   }
 
-  int tokenStartPos = 0;
-  int tokenSize = 0;
-  for (int i = 0; i <= strSize - dSize; ++i) {
+  size_t tokenStartPos = 0;
+  size_t tokenSize = 0;
+  for (size_t i = 0; i <= strSize - dSize; ++i) {
     if (atDelim(&s[i], delim)) {
       if (!ignoreEmpty || tokenSize > 0) {
         *out++ = conv(StringPiece(&s[tokenStartPos], tokenSize));
@@ -335,9 +335,8 @@ void internalSplit(DelimT delim, StringPiece sp, OutputIterator out,
       ++tokenSize;
     }
   }
-
+  tokenSize = strSize - tokenStartPos;
   if (!ignoreEmpty || tokenSize > 0) {
-    tokenSize = strSize - tokenStartPos;
     *out++ = conv(StringPiece(&s[tokenStartPos], tokenSize));
   }
 }
@@ -450,9 +449,20 @@ split(const Delim& delimiter,
 
 namespace detail {
 
+/*
+ * If a type can have its string size determined cheaply, we can more
+ * efficiently append it in a loop (see internalJoinAppend). Note that the
+ * struct need not conform to the std::string api completely (ex. does not need
+ * to implement append()).
+ */
+template <class T> struct IsSizableString {
+  enum { value = IsSomeString<T>::value
+         || std::is_same<T, StringPiece>::value };
+};
+
 template <class Iterator>
-struct IsStringContainerIterator :
-  IsSomeString<typename std::iterator_traits<Iterator>::value_type> {
+struct IsSizableStringContainerIterator :
+  IsSizableString<typename std::iterator_traits<Iterator>::value_type> {
 };
 
 template <class Delim, class Iterator, class String>
@@ -473,7 +483,7 @@ void internalJoinAppend(Delim delimiter,
 }
 
 template <class Delim, class Iterator, class String>
-typename std::enable_if<IsStringContainerIterator<Iterator>::value>::type
+typename std::enable_if<IsSizableStringContainerIterator<Iterator>::value>::type
 internalJoin(Delim delimiter,
              Iterator begin,
              Iterator end,
@@ -493,7 +503,8 @@ internalJoin(Delim delimiter,
 }
 
 template <class Delim, class Iterator, class String>
-typename std::enable_if<!IsStringContainerIterator<Iterator>::value>::type
+typename
+std::enable_if<!IsSizableStringContainerIterator<Iterator>::value>::type
 internalJoin(Delim delimiter,
              Iterator begin,
              Iterator end,
@@ -604,9 +615,9 @@ bool hexlify(const InputString& input, OutputString& output,
   if (!append_output) output.clear();
 
   static char hexValues[] = "0123456789abcdef";
-  int j = output.size();
+  auto j = output.size();
   output.resize(2 * input.size() + output.size());
-  for (int i = 0; i < input.size(); ++i) {
+  for (size_t i = 0; i < input.size(); ++i) {
     int ch = input[i];
     output[j++] = hexValues[(ch >> 4) & 0xf];
     output[j++] = hexValues[ch & 0xf];
@@ -628,7 +639,7 @@ bool unhexlify(const InputString& input, OutputString& output) {
            -1;
   };
 
-  for (int i = 0; i < input.size(); i += 2) {
+  for (size_t i = 0; i < input.size(); i += 2) {
     int highBits = unhex(input[i]);
     int lowBits = unhex(input[i + 1]);
     if (highBits < 0 || lowBits < 0) {