Revert change "Fix "unsafe narrowing" warnings in absl, 4/n.".

The change breaks existing code by changing the return type of absl::bit_width.

PiperOrigin-RevId: 465295951
Change-Id: Id4ce7c2ac3699ce22aa2b4851a949f9e0104a3d7

absl/numeric/bits.h

@@ -131,9 +131,10 @@ has_single_bit(T x) noexcept {
 // fractional part discarded.
 template <class T>
 ABSL_INTERNAL_CONSTEXPR_CLZ inline
-    typename std::enable_if<std::is_unsigned<T>::value, int>::type
+    typename std::enable_if<std::is_unsigned<T>::value, T>::type
     bit_width(T x) noexcept {
-  return std::numeric_limits<T>::digits - countl_zero(x);
+  return std::numeric_limits<T>::digits -
+         static_cast<unsigned int>(countl_zero(x));
 }
 
 // Returns: If x == 0, 0; otherwise the maximal value y such that

absl/strings/ascii.cc

@@ -157,13 +157,13 @@ ABSL_DLL const char kToUpper[256] = {
 
 void AsciiStrToLower(std::string* s) {
   for (auto& ch : *s) {
-    ch = absl::ascii_tolower(static_cast<unsigned char>(ch));
+    ch = absl::ascii_tolower(ch);
   }
 }
 
 void AsciiStrToUpper(std::string* s) {
   for (auto& ch : *s) {
-    ch = absl::ascii_toupper(static_cast<unsigned char>(ch));
+    ch = absl::ascii_toupper(ch);
   }
 }
 
@@ -183,17 +183,17 @@ void RemoveExtraAsciiWhitespace(std::string* str) {
   for (; input_it < input_end; ++input_it) {
     if (is_ws) {
       // Consecutive whitespace?  Keep only the last.
-      is_ws = absl::ascii_isspace(static_cast<unsigned char>(*input_it));
+      is_ws = absl::ascii_isspace(*input_it);
       if (is_ws) --output_it;
     } else {
-      is_ws = absl::ascii_isspace(static_cast<unsigned char>(*input_it));
+      is_ws = absl::ascii_isspace(*input_it);
     }
 
     *output_it = *input_it;
     ++output_it;
   }
 
-  str->erase(static_cast<size_t>(output_it - &(*str)[0]));
+  str->erase(output_it - &(*str)[0]);
 }
 
 ABSL_NAMESPACE_END

absl/strings/charconv.cc

@@ -65,8 +65,6 @@ struct FloatTraits;
 
 template <>
 struct FloatTraits<double> {
-  using mantissa_t = uint64_t;
-
   // The number of mantissa bits in the given float type.  This includes the
   // implied high bit.
   static constexpr int kTargetMantissaBits = 53;
@@ -105,7 +103,7 @@ struct FloatTraits<double> {
   // a normal value is made, or it must be less narrow than that, in which case
   // `exponent` must be exactly kMinNormalExponent, and a subnormal value is
   // made.
-  static double Make(mantissa_t mantissa, int exponent, bool sign) {
+  static double Make(uint64_t mantissa, int exponent, bool sign) {
 #ifndef ABSL_BIT_PACK_FLOATS
     // Support ldexp no matter which namespace it's in.  Some platforms
     // incorrectly don't put it in namespace std.
@@ -118,10 +116,8 @@ struct FloatTraits<double> {
     if (mantissa > kMantissaMask) {
       // Normal value.
       // Adjust by 1023 for the exponent representation bias, and an additional
-      // 52 due to the implied decimal point in the IEEE mantissa
-      // representation.
-      dbl += static_cast<uint64_t>(exponent + 1023 + kTargetMantissaBits - 1)
-             << 52;
+      // 52 due to the implied decimal point in the IEEE mantissa represenation.
+      dbl += uint64_t{exponent + 1023u + kTargetMantissaBits - 1} << 52;
       mantissa &= kMantissaMask;
     } else {
       // subnormal value
@@ -138,20 +134,16 @@ struct FloatTraits<double> {
 // members and methods.
 template <>
 struct FloatTraits<float> {
-  using mantissa_t = uint32_t;
-
   static constexpr int kTargetMantissaBits = 24;
   static constexpr int kMaxExponent = 104;
   static constexpr int kMinNormalExponent = -149;
-
   static float MakeNan(const char* tagp) {
     // Support nanf no matter which namespace it's in.  Some platforms
     // incorrectly don't put it in namespace std.
     using namespace std;  // NOLINT
     return nanf(tagp);
   }
-
-  static float Make(mantissa_t mantissa, int exponent, bool sign) {
+  static float Make(uint32_t mantissa, int exponent, bool sign) {
 #ifndef ABSL_BIT_PACK_FLOATS
     // Support ldexpf no matter which namespace it's in.  Some platforms
     // incorrectly don't put it in namespace std.
@@ -165,8 +157,7 @@ struct FloatTraits<float> {
       // Normal value.
       // Adjust by 127 for the exponent representation bias, and an additional
       // 23 due to the implied decimal point in the IEEE mantissa represenation.
-      flt += static_cast<uint32_t>(exponent + 127 + kTargetMantissaBits - 1)
-             << 23;
+      flt += uint32_t{exponent + 127u + kTargetMantissaBits - 1} << 23;
       mantissa &= kMantissaMask;
     } else {
       // subnormal value
@@ -251,9 +242,9 @@ struct CalculatedFloat {
 
 // Returns the bit width of the given uint128.  (Equivalently, returns 128
 // minus the number of leading zero bits.)
-int BitWidth(uint128 value) {
+unsigned BitWidth(uint128 value) {
   if (Uint128High64(value) == 0) {
-    return bit_width(Uint128Low64(value));
+    return static_cast<unsigned>(bit_width(Uint128Low64(value)));
   }
   return 128 - countl_zero(Uint128High64(value));
 }
@@ -346,10 +337,8 @@ void EncodeResult(const CalculatedFloat& calculated, bool negative,
     *value = negative ? -0.0 : 0.0;
     return;
   }
-  *value = FloatTraits<FloatType>::Make(
-      static_cast<typename FloatTraits<FloatType>::mantissa_t>(
-          calculated.mantissa),
-      calculated.exponent, negative);
+  *value = FloatTraits<FloatType>::Make(calculated.mantissa,
+                                        calculated.exponent, negative);
 }
 
 // Returns the given uint128 shifted to the right by `shift` bits, and rounds
@@ -530,7 +519,7 @@ CalculatedFloat CalculateFromParsedHexadecimal(
     const strings_internal::ParsedFloat& parsed_hex) {
   uint64_t mantissa = parsed_hex.mantissa;
   int exponent = parsed_hex.exponent;
-  int mantissa_width = bit_width(mantissa);
+  auto mantissa_width = static_cast<unsigned>(bit_width(mantissa));
   const int shift = NormalizedShiftSize<FloatType>(mantissa_width, exponent);
   bool result_exact;
   exponent += shift;

absl/strings/cord.cc

@@ -20,7 +20,6 @@
 #include <cstdio>
 #include <cstdlib>
 #include <iomanip>
-#include <ios>
 #include <iostream>
 #include <limits>
 #include <ostream>
@@ -185,7 +184,7 @@ inline void Cord::InlineRep::reduce_size(size_t n) {
   assert(tag >= n);
   tag -= n;
   memset(data_.as_chars() + tag, 0, n);
-  set_inline_size(tag);
+  set_inline_size(static_cast<char>(tag));
 }
 
 inline void Cord::InlineRep::remove_prefix(size_t n) {
@@ -1099,7 +1098,7 @@ Cord Cord::ChunkIterator::AdvanceAndReadBytes(size_t n) {
                          : current_leaf_;
   const char* data = payload->IsExternal() ? payload->external()->base
                                            : payload->flat()->Data();
-  const size_t offset = static_cast<size_t>(current_chunk_.data() - data);
+  const size_t offset = current_chunk_.data() - data;
 
   auto* tree = CordRepSubstring::Substring(payload, offset, n);
   subcord.contents_.EmplaceTree(VerifyTree(tree), method);
@@ -1309,7 +1308,7 @@ static bool VerifyNode(CordRep* root, CordRep* start_node,
 
 std::ostream& operator<<(std::ostream& out, const Cord& cord) {
   for (absl::string_view chunk : cord.Chunks()) {
-    out.write(chunk.data(), static_cast<std::streamsize>(chunk.size()));
+    out.write(chunk.data(), chunk.size());
   }
   return out;
 }

absl/strings/cord_buffer.h

@@ -411,12 +411,8 @@ class CordBuffer {
 
   // Power2 functions
   static bool IsPow2(size_t size) { return absl::has_single_bit(size); }
-  static size_t Log2Floor(size_t size) {
-    return static_cast<size_t>(absl::bit_width(size) - 1);
-  }
-  static size_t Log2Ceil(size_t size) {
-    return static_cast<size_t>(absl::bit_width(size - 1));
-  }
+  static size_t Log2Floor(size_t size) { return absl::bit_width(size) - 1; }
+  static size_t Log2Ceil(size_t size) { return absl::bit_width(size - 1); }
 
   // Implementation of `CreateWithCustomLimit()`.
   // This implementation allows for future memory allocation hints to

absl/strings/numbers.cc

@@ -190,32 +190,32 @@ char* numbers_internal::FastIntToBuffer(uint32_t i, char* buffer) {
     if (i >= 1000) goto lt10_000;
     digits = i / 100;
     i -= digits * 100;
-    *buffer++ = '0' + static_cast<char>(digits);
+    *buffer++ = '0' + digits;
     goto lt100;
   }
   if (i < 1000000) {  //    1,000,000
     if (i >= 100000) goto lt1_000_000;
     digits = i / 10000;  //    10,000
     i -= digits * 10000;
-    *buffer++ = '0' + static_cast<char>(digits);
+    *buffer++ = '0' + digits;
     goto lt10_000;
   }
   if (i < 100000000) {  //    100,000,000
     if (i >= 10000000) goto lt100_000_000;
     digits = i / 1000000;  //   1,000,000
     i -= digits * 1000000;
-    *buffer++ = '0' + static_cast<char>(digits);
+    *buffer++ = '0' + digits;
     goto lt1_000_000;
   }
   // we already know that i < 1,000,000,000
   digits = i / 100000000;  //   100,000,000
   i -= digits * 100000000;
-  *buffer++ = '0' + static_cast<char>(digits);
+  *buffer++ = '0' + digits;
   goto lt100_000_000;
 }
 
 char* numbers_internal::FastIntToBuffer(int32_t i, char* buffer) {
-  uint32_t u = static_cast<uint32_t>(i);
+  uint32_t u = i;
   if (i < 0) {
     *buffer++ = '-';
     // We need to do the negation in modular (i.e., "unsigned")
@@ -268,7 +268,7 @@ char* numbers_internal::FastIntToBuffer(uint64_t i, char* buffer) {
 }
 
 char* numbers_internal::FastIntToBuffer(int64_t i, char* buffer) {
-  uint64_t u = static_cast<uint64_t>(i);
+  uint64_t u = i;
   if (i < 0) {
     *buffer++ = '-';
     u = 0 - u;
@@ -329,7 +329,7 @@ static std::pair<uint64_t, uint64_t> PowFive(uint64_t num, int expfive) {
     result = Mul32(result, 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5 * 5);
     expfive -= 13;
   }
-  constexpr uint32_t powers_of_five[13] = {
+  constexpr int powers_of_five[13] = {
       1,
       5,
       5 * 5,
@@ -404,14 +404,14 @@ static ExpDigits SplitToSix(const double value) {
   // we multiply it by 65536 and see if the fractional part is close to 32768.
   // (The number doesn't have to be a power of two,but powers of two are faster)
   uint64_t d64k = d * 65536;
-  uint32_t dddddd;  // A 6-digit decimal integer.
+  int dddddd;  // A 6-digit decimal integer.
   if ((d64k % 65536) == 32767 || (d64k % 65536) == 32768) {
     // OK, it's fairly likely that precision was lost above, which is
     // not a surprise given only 52 mantissa bits are available.  Therefore
     // redo the calculation using 128-bit numbers.  (64 bits are not enough).
 
     // Start out with digits rounded down; maybe add one below.
-    dddddd = static_cast<uint32_t>(d64k / 65536);
+    dddddd = static_cast<int>(d64k / 65536);
 
     // mantissa is a 64-bit integer representing M.mmm... * 2^63.  The actual
     // value we're representing, of course, is M.mmm... * 2^exp2.
@@ -461,7 +461,7 @@ static ExpDigits SplitToSix(const double value) {
     }
   } else {
     // Here, we are not close to the edge.
-    dddddd = static_cast<uint32_t>((d64k + 32768) / 65536);
+    dddddd = static_cast<int>((d64k + 32768) / 65536);
   }
   if (dddddd == 1000000) {
     dddddd = 100000;
@@ -469,7 +469,7 @@ static ExpDigits SplitToSix(const double value) {
   }
   exp_dig.exponent = exp;
 
-  uint32_t two_digits = dddddd / 10000;
+  int two_digits = dddddd / 10000;
   dddddd -= two_digits * 10000;
   numbers_internal::PutTwoDigits(two_digits, &exp_dig.digits[0]);
 
@@ -499,7 +499,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
     if (std::signbit(d)) *out++ = '-';
     *out++ = '0';
     *out = 0;
-    return static_cast<size_t>(out - buffer);
+    return out - buffer;
   }
   if (d < 0) {
     *out++ = '-';
@@ -507,7 +507,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
   }
   if (d > std::numeric_limits<double>::max()) {
     strcpy(out, "inf");  // NOLINT(runtime/printf)
-    return static_cast<size_t>(out + 3 - buffer);
+    return out + 3 - buffer;
   }
 
   auto exp_dig = SplitToSix(d);
@@ -519,7 +519,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
     case 5:
       memcpy(out, &digits[0], 6), out += 6;
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
     case 4:
       memcpy(out, &digits[0], 5), out += 5;
       if (digits[5] != '0') {
@@ -527,7 +527,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
         *out++ = digits[5];
       }
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
     case 3:
       memcpy(out, &digits[0], 4), out += 4;
       if ((digits[5] | digits[4]) != '0') {
@@ -536,7 +536,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
         if (digits[5] != '0') *out++ = digits[5];
       }
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
     case 2:
       memcpy(out, &digits[0], 3), out += 3;
       *out++ = '.';
@@ -545,7 +545,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
       while (out[-1] == '0') --out;
       if (out[-1] == '.') --out;
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
     case 1:
       memcpy(out, &digits[0], 2), out += 2;
       *out++ = '.';
@@ -554,7 +554,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
       while (out[-1] == '0') --out;
       if (out[-1] == '.') --out;
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
     case 0:
       memcpy(out, &digits[0], 1), out += 1;
       *out++ = '.';
@@ -563,7 +563,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
       while (out[-1] == '0') --out;
       if (out[-1] == '.') --out;
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
     case -4:
       out[2] = '0';
       ++out;
@@ -582,7 +582,7 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
       out += 6;
       while (out[-1] == '0') --out;
       *out = 0;
-      return static_cast<size_t>(out - buffer);
+      return out - buffer;
   }
   assert(exp < -4 || exp >= 6);
   out[0] = digits[0];
@@ -601,12 +601,12 @@ size_t numbers_internal::SixDigitsToBuffer(double d, char* const buffer) {
   if (exp > 99) {
     int dig1 = exp / 100;
     exp -= dig1 * 100;
-    *out++ = '0' + static_cast<char>(dig1);
+    *out++ = '0' + dig1;
   }
-  PutTwoDigits(static_cast<uint32_t>(exp), out);
+  PutTwoDigits(exp, out);
   out += 2;
   *out = 0;
-  return static_cast<size_t>(out - buffer);
+  return out - buffer;
 }
 
 namespace {
@@ -642,12 +642,10 @@ inline bool safe_parse_sign_and_base(absl::string_view* text /*inout*/,
   int base = *base_ptr;
 
   // Consume whitespace.
-  while (start < end &&
-         absl::ascii_isspace(static_cast<unsigned char>(start[0]))) {
+  while (start < end && absl::ascii_isspace(start[0])) {
     ++start;
   }
-  while (start < end &&
-         absl::ascii_isspace(static_cast<unsigned char>(end[-1]))) {
+  while (start < end && absl::ascii_isspace(end[-1])) {
     --end;
   }
   if (start >= end) {
@@ -696,7 +694,7 @@ inline bool safe_parse_sign_and_base(absl::string_view* text /*inout*/,
   } else {
     return false;
   }
-  *text = absl::string_view(start, static_cast<size_t>(end - start));
+  *text = absl::string_view(start, end - start);
   *base_ptr = base;
   return true;
 }
@@ -922,18 +920,17 @@ inline bool safe_parse_positive_int(absl::string_view text, int base,
   const IntType vmax = std::numeric_limits<IntType>::max();
   assert(vmax > 0);
   assert(base >= 0);
-  const IntType base_inttype = static_cast<IntType>(base);
-  assert(vmax >= base_inttype);
+  assert(vmax >= static_cast<IntType>(base));
   const IntType vmax_over_base = LookupTables<IntType>::kVmaxOverBase[base];
   assert(base < 2 ||
-         std::numeric_limits<IntType>::max() / base_inttype == vmax_over_base);
+         std::numeric_limits<IntType>::max() / base == vmax_over_base);
   const char* start = text.data();
   const char* end = start + text.size();
   // loop over digits
   for (; start < end; ++start) {
     unsigned char c = static_cast<unsigned char>(start[0]);
-    IntType digit = static_cast<IntType>(kAsciiToInt[c]);
-    if (digit >= base_inttype) {
+    int digit = kAsciiToInt[c];
+    if (digit >= base) {
       *value_p = value;
       return false;
     }
@@ -941,7 +938,7 @@ inline bool safe_parse_positive_int(absl::string_view text, int base,
       *value_p = vmax;
       return false;
     }
-    value *= base_inttype;
+    value *= base;
     if (value > vmax - digit) {
       *value_p = vmax;
       return false;

absl/strings/str_cat.cc

@@ -56,7 +56,7 @@ AlphaNum::AlphaNum(Dec dec) {
     *--writer = '0' + (value % 10);
     value /= 10;
   }
-  *--writer = '0' + static_cast<char>(value);
+  *--writer = '0' + value;
   if (neg) *--writer = '-';
 
   ptrdiff_t fillers = writer - minfill;
@@ -73,7 +73,7 @@ AlphaNum::AlphaNum(Dec dec) {
     if (add_sign_again) *--writer = '-';
   }
 
-  piece_ = absl::string_view(writer, static_cast<size_t>(end - writer));
+  piece_ = absl::string_view(writer, end - writer);
 }
 
 // ----------------------------------------------------------------------

absl/strings/string_view.cc

@@ -32,7 +32,7 @@ void WritePadding(std::ostream& o, size_t pad) {
   memset(fill_buf, o.fill(), sizeof(fill_buf));
   while (pad) {
     size_t n = std::min(pad, sizeof(fill_buf));
-    o.write(fill_buf, static_cast<std::streamsize>(n));
+    o.write(fill_buf, n);
     pad -= n;
   }
 }
@@ -63,7 +63,7 @@ std::ostream& operator<<(std::ostream& o, string_view piece) {
     size_t lpad = 0;
     size_t rpad = 0;
     if (static_cast<size_t>(o.width()) > piece.size()) {
-      size_t pad = static_cast<size_t>(o.width()) - piece.size();
+      size_t pad = o.width() - piece.size();
       if ((o.flags() & o.adjustfield) == o.left) {
         rpad = pad;
       } else {
@@ -71,7 +71,7 @@ std::ostream& operator<<(std::ostream& o, string_view piece) {
       }
     }
     if (lpad) WritePadding(o, lpad);
-    o.write(piece.data(), static_cast<std::streamsize>(piece.size()));
+    o.write(piece.data(), piece.size());
     if (rpad) WritePadding(o, rpad);
     o.width(0);
   }
@@ -86,7 +86,7 @@ string_view::size_type string_view::find(string_view s,
   }
   const char* result =
       strings_internal::memmatch(ptr_ + pos, length_ - pos, s.ptr_, s.length_);
-  return result ? static_cast<size_type>(result - ptr_) : npos;
+  return result ? result - ptr_ : npos;
 }
 
 string_view::size_type string_view::find(char c, size_type pos) const noexcept {
@@ -95,7 +95,7 @@ string_view::size_type string_view::find(char c, size_type pos) const noexcept {
   }
   const char* result =
       static_cast<const char*>(memchr(ptr_ + pos, c, length_ - pos));
-  return result != nullptr ? static_cast<size_type>(result - ptr_) : npos;
+  return result != nullptr ? result - ptr_ : npos;
 }
 
 string_view::size_type string_view::rfind(string_view s,
@@ -104,7 +104,7 @@ string_view::size_type string_view::rfind(string_view s,
   if (s.empty()) return std::min(length_, pos);
   const char* last = ptr_ + std::min(length_ - s.length_, pos) + s.length_;
   const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);
-  return result != last ? static_cast<size_type>(result - ptr_) : npos;
+  return result != last ? result - ptr_ : npos;
 }
 
 // Search range is [0..pos] inclusive.  If pos == npos, search everything.

absl/strings/substitute.cc

@@ -40,8 +40,7 @@ void SubstituteAndAppendArray(std::string* output, absl::string_view format,
                      absl::CEscape(format).c_str());
 #endif
         return;
-      } else if (absl::ascii_isdigit(
-                     static_cast<unsigned char>(format[i + 1]))) {
+      } else if (absl::ascii_isdigit(format[i + 1])) {
         int index = format[i + 1] - '0';
         if (static_cast<size_t>(index) >= num_args) {
 #ifndef NDEBUG
@@ -81,7 +80,7 @@ void SubstituteAndAppendArray(std::string* output, absl::string_view format,
   char* target = &(*output)[original_size];
   for (size_t i = 0; i < format.size(); i++) {
     if (format[i] == '$') {
-      if (absl::ascii_isdigit(static_cast<unsigned char>(format[i + 1]))) {
+      if (absl::ascii_isdigit(format[i + 1])) {
         const absl::string_view src = args_array[format[i + 1] - '0'];
         target = std::copy(src.begin(), src.end(), target);
         ++i;  // Skip next char.
@@ -111,8 +110,7 @@ Arg::Arg(const void* value) {
     } while (num != 0);
     *--ptr = 'x';
     *--ptr = '0';
-    piece_ = absl::string_view(
-        ptr, static_cast<size_t>(scratch_ + sizeof(scratch_) - ptr));
+    piece_ = absl::string_view(ptr, scratch_ + sizeof(scratch_) - ptr);
   }
 }
 
@@ -134,7 +132,7 @@ Arg::Arg(Hex hex) {
     beg = writer;
   }
 
-  piece_ = absl::string_view(beg, static_cast<size_t>(end - beg));
+  piece_ = absl::string_view(beg, end - beg);
 }
 
 // TODO(jorg): Don't duplicate so much code between here and str_cat.cc
@@ -149,7 +147,7 @@ Arg::Arg(Dec dec) {
     *--writer = '0' + (value % 10);
     value /= 10;
   }
-  *--writer = '0' + static_cast<char>(value);
+  *--writer = '0' + value;
   if (neg) *--writer = '-';
 
   ptrdiff_t fillers = writer - minfill;
@@ -166,7 +164,7 @@ Arg::Arg(Dec dec) {
     if (add_sign_again) *--writer = '-';
   }
 
-  piece_ = absl::string_view(writer, static_cast<size_t>(end - writer));
+  piece_ = absl::string_view(writer, end - writer);
 }
 
 }  // namespace substitute_internal