1// Copyright 2011 Google Inc. All Rights Reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7// http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15#ifndef NINJA_STRINGPIECE_H_
16#define NINJA_STRINGPIECE_H_
17
18#include <string>
19
20#include <string.h>
21
22/// StringPiece represents a slice of a string whose memory is managed
23/// externally. It is useful for reducing the number of std::strings
24/// we need to allocate.
25struct StringPiece {
26 typedef const char* const_iterator;
27
28 StringPiece() : str_(NULL), len_(0) {}
29
30 /// The constructors intentionally allow for implicit conversions.
31 StringPiece(const std::string& str) : str_(str.data()), len_(str.size()) {}
32 StringPiece(const char* str) : str_(str), len_(strlen(str)) {}
33
34 StringPiece(const char* str, size_t len) : str_(str), len_(len) {}
35
36 bool operator==(const StringPiece& other) const {
37 return len_ == other.len_ && memcmp(str_, other.str_, len_) == 0;
38 }
39
40 bool operator!=(const StringPiece& other) const {
41 return !(*this == other);
42 }
43
44 /// Convert the slice into a full-fledged std::string, copying the
45 /// data into a new string.
46 std::string AsString() const {
47 return len_ ? std::string(str_, len_) : std::string();
48 }
49
50 const_iterator begin() const {
51 return str_;
52 }
53
54 const_iterator end() const {
55 return str_ + len_;
56 }
57
58 char operator[](size_t pos) const {
59 return str_[pos];
60 }
61
62 size_t size() const {
63 return len_;
64 }
65
66 const char* str_;
67 size_t len_;
68};
69
70#endif // NINJA_STRINGPIECE_H_
71