libc/src/string/strspn.cpp

   1 //===-- Implementation of strspn ------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/string/strspn.h"
  10
  11 #include "src/__support/common.h"
  12 #include "utils/CPP/Bitset.h"
  13 #include <stddef.h>
  14
  15 namespace __llvm_libc {
  16
  17 size_t LLVM_LIBC_ENTRYPOINT(strspn)(const char *src, const char *segment) {
  18   const char *initial = src;
  19   cpp::Bitset<256> bitset;
  20
  21   for (; *segment; ++segment)
  22     bitset.set(*segment);
  23   for (; *src && bitset.test(*src); ++src)
  24     ;
  25   return src - initial;
  26 }
  27
  28 } // namespace __llvm_libc