xref: /aosp_15_r20/external/llvm-libc/src/string/strspn.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
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/CPP/bitset.h"
12 #include "src/__support/common.h"
13 #include "src/__support/macros/config.h"
14 #include <stddef.h>
15 
16 namespace LIBC_NAMESPACE_DECL {
17 
18 LLVM_LIBC_FUNCTION(size_t, strspn, (const char *src, const char *segment)) {
19   const char *initial = src;
20   cpp::bitset<256> bitset;
21 
22   for (; *segment; ++segment)
23     bitset.set(*reinterpret_cast<const unsigned char *>(segment));
24   for (; *src && bitset.test(*reinterpret_cast<const unsigned char *>(src));
25        ++src)
26     ;
27   return src - initial;
28 }
29 
30 } // namespace LIBC_NAMESPACE_DECL
31