Use const and static for member functions

This shows that these are member functions that do not modify a class's data.

absl/crc/internal/crc.cc

@@ -261,7 +261,7 @@ void CRC32::Extend(uint32_t* crc, const void* bytes, size_t length) const {
   const uint8_t* e = p + length;
   uint32_t l = *crc;
 
-  auto step_one_byte = [this, &p, &l] () {
+  auto step_one_byte = [this, &p, &l]() {
     int c = (l & 0xff) ^ *p++;
     l = this->table0_[c] ^ (l >> 8);
   };
@@ -359,7 +359,7 @@ void CRC32::Extend(uint32_t* crc, const void* bytes, size_t length) const {
 
 void CRC32::ExtendByZeroesImpl(uint32_t* crc, size_t length,
                                const uint32_t zeroes_table[256],
-                               const uint32_t poly_table[256]) const {
+                               const uint32_t poly_table[256]) {
   if (length != 0) {
     uint32_t l = *crc;
     // For each ZEROES_BASE_LG bits in length

absl/crc/internal/crc_internal.h

@@ -118,9 +118,9 @@ class CRC32 : public CRCImpl {
   //
   // These will be set to reverse_zeroes_ and reverse_table0_ for Unextend, and
   // CRC32::zeroes_ and CRC32::table0_ for Extend.
-  void ExtendByZeroesImpl(uint32_t* crc, size_t length,
+  static void ExtendByZeroesImpl(uint32_t* crc, size_t length,
                                  const uint32_t zeroes_table[256],
-                          const uint32_t poly_table[256]) const;
+                                 const uint32_t poly_table[256]);
 
   uint32_t table0_[256];  // table of byte extensions
   uint32_t zeroes_[256];  // table of zero extensions

absl/strings/cord_buffer.h

@@ -160,7 +160,6 @@ class CordBuffer {
   // for more information on buffer capacities and intended usage.
   static CordBuffer CreateWithDefaultLimit(size_t capacity);
 
-
   // CordBuffer::CreateWithCustomLimit()
   //
   // Creates a CordBuffer instance of the desired `capacity` rounded to an
@@ -336,7 +335,7 @@ class CordBuffer {
     }
 
     // Returns the available area of the internal SSO data
-    absl::Span<char> long_available() {
+    absl::Span<char> long_available() const {
       assert(!is_short());
       const size_t length = long_rep.rep->length;
       return absl::Span<char>(long_rep.rep->Data() + length,

absl/strings/internal/str_format/float_conversion.cc

@@ -1015,7 +1015,7 @@ struct Buffer {
     --end;
   }
 
-  char &back() {
+  char &back() const {
     assert(begin < end);
     return end[-1];
   }

absl/strings/str_split.cc

@@ -60,19 +60,23 @@ absl::string_view GenericFind(absl::string_view text,
 // Finds using absl::string_view::find(), therefore the length of the found
 // delimiter is delimiter.length().
 struct LiteralPolicy {
-  size_t Find(absl::string_view text, absl::string_view delimiter, size_t pos) {
+  static size_t Find(absl::string_view text, absl::string_view delimiter,
+                     size_t pos) {
     return text.find(delimiter, pos);
   }
-  size_t Length(absl::string_view delimiter) { return delimiter.length(); }
+  static size_t Length(absl::string_view delimiter) {
+    return delimiter.length();
+  }
 };
 
 // Finds using absl::string_view::find_first_of(), therefore the length of the
 // found delimiter is 1.
 struct AnyOfPolicy {
-  size_t Find(absl::string_view text, absl::string_view delimiter, size_t pos) {
+  static size_t Find(absl::string_view text, absl::string_view delimiter,
+                     size_t pos) {
     return text.find_first_of(delimiter, pos);
   }
-  size_t Length(absl::string_view /* delimiter */) { return 1; }
+  static size_t Length(absl::string_view /* delimiter */) { return 1; }
 };
 
 }  // namespace
@@ -123,8 +127,7 @@ ByLength::ByLength(ptrdiff_t length) : length_(length) {
   ABSL_RAW_CHECK(length > 0, "");
 }
 
-absl::string_view ByLength::Find(absl::string_view text,
-                                      size_t pos) const {
+absl::string_view ByLength::Find(absl::string_view text, size_t pos) const {
   pos = std::min(pos, text.size());  // truncate `pos`
   absl::string_view substr = text.substr(pos);
   // If the string is shorter than the chunk size we say we