Cleanup `//absl/strings/internal/memutil.h`

`memmatch()` is only used in `string_view.cc`, so move it there.
The moving of `memmatch()` to `string_view.cc` decouples `string_view`
from `memutil`, which will allow us to move `string_view` into its
own target in a followup.

The only other function that is used is `memcasecmp()`, so delete
all other functions.

PiperOrigin-RevId: 547238386
Change-Id: Id6fad47dd24191c8e8f26dd923fffa1007c8db4a

1 files changed, 2 insertions, 77 deletions

diff --git a/absl/strings/internal/memutil.cc b/absl/strings/internal/memutil.cc
index 44996a75..e2e7347c 100644
--- a/absl/strings/internal/memutil.cc
+++ b/absl/strings/internal/memutil.cc
@@ -16,6 +16,8 @@
 
 #include <cstdlib>
 
+#include "absl/strings/ascii.h"
+
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace strings_internal {
@@ -33,83 +35,6 @@ int memcasecmp(const char* s1, const char* s2, size_t len) {
   return 0;
 }
 
-char* memdup(const char* s, size_t slen) {
-  void* copy;
-  if ((copy = malloc(slen)) == nullptr) return nullptr;
-  memcpy(copy, s, slen);
-  return reinterpret_cast<char*>(copy);
-}
-
-char* memrchr(const char* s, int c, size_t slen) {
-  for (const char* e = s + slen - 1; e >= s; e--) {
-    if (*e == c) return const_cast<char*>(e);
-  }
-  return nullptr;
-}
-
-size_t memspn(const char* s, size_t slen, const char* accept) {
-  const char* p = s;
-  const char* spanp;
-  char c, sc;
-
-cont:
-  c = *p++;
-  if (slen-- == 0)
-    return static_cast<size_t>(p - 1 - s);
-  for (spanp = accept; (sc = *spanp++) != '\0';)
-    if (sc == c) goto cont;
-  return static_cast<size_t>(p - 1 - s);
-}
-
-size_t memcspn(const char* s, size_t slen, const char* reject) {
-  const char* p = s;
-  const char* spanp;
-  char c, sc;
-
-  while (slen-- != 0) {
-    c = *p++;
-    for (spanp = reject; (sc = *spanp++) != '\0';)
-      if (sc == c)
-        return static_cast<size_t>(p - 1 - s);
-  }
-  return static_cast<size_t>(p - s);
-}
-
-char* mempbrk(const char* s, size_t slen, const char* accept) {
-  const char* scanp;
-  int sc;
-
-  for (; slen; ++s, --slen) {
-    for (scanp = accept; (sc = *scanp++) != '\0';)
-      if (sc == *s) return const_cast<char*>(s);
-  }
-  return nullptr;
-}
-
-// This is significantly faster for case-sensitive matches with very
-// few possible matches.  See unit test for benchmarks.
-const char* memmatch(const char* phaystack, size_t haylen, const char* pneedle,
-                     size_t neelen) {
-  if (0 == neelen) {
-    return phaystack;  // even if haylen is 0
-  }
-  if (haylen < neelen) return nullptr;
-
-  const char* match;
-  const char* hayend = phaystack + haylen - neelen + 1;
-  // A static cast is used here to work around the fact that memchr returns
-  // a void* on Posix-compliant systems and const void* on Windows.
-  while (
-      (match = static_cast<const char*>(memchr(
-           phaystack, pneedle[0], static_cast<size_t>(hayend - phaystack))))) {
-    if (memcmp(match, pneedle, neelen) == 0)
-      return match;
-    else
-      phaystack = match + 1;
-  }
-  return nullptr;
-}
-
 }  // namespace strings_internal
 ABSL_NAMESPACE_END
 }  // namespace absl