1 files changed, 146 insertions, 0 deletions
diff --git a/include/grpcpp/impl/codegen/string_ref.h b/include/grpcpp/impl/codegen/string_ref.h
new file mode 100644
index 0000000000..5d55fc4180
--- /dev/null
+++ b/include/grpcpp/impl/codegen/string_ref.h
@@ -0,0 +1,146 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPCPP_IMPL_CODEGEN_STRING_REF_H
+#define GRPCPP_IMPL_CODEGEN_STRING_REF_H
+
+#include <string.h>
+
+#include <algorithm>
+#include <iosfwd>
+#include <iostream>
+#include <iterator>
+
+#include <grpcpp/impl/codegen/config.h>
+
+namespace grpc {
+
+/// This class is a non owning reference to a string.
+///
+/// It should be a strict subset of the upcoming std::string_ref.
+///
+/// \see http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3442.html
+///
+/// The constexpr is dropped or replaced with const for legacy compiler
+/// compatibility.
+class string_ref {
+ public:
+  /// types
+  typedef const char* const_iterator;
+  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+  /// constants
+  const static size_t npos;
+
+  /// construct/copy.
+  string_ref() : data_(nullptr), length_(0) {}
+  string_ref(const string_ref& other)
+      : data_(other.data_), length_(other.length_) {}
+  string_ref& operator=(const string_ref& rhs) {
+    data_ = rhs.data_;
+    length_ = rhs.length_;
+    return *this;
+  }
+
+  string_ref(const char* s) : data_(s), length_(strlen(s)) {}
+  string_ref(const char* s, size_t l) : data_(s), length_(l) {}
+  string_ref(const grpc::string& s) : data_(s.data()), length_(s.length()) {}
+
+  /// iterators
+  const_iterator begin() const { return data_; }
+  const_iterator end() const { return data_ + length_; }
+  const_iterator cbegin() const { return data_; }
+  const_iterator cend() const { return data_ + length_; }
+  const_reverse_iterator rbegin() const {
+    return const_reverse_iterator(end());
+  }
+  const_reverse_iterator rend() const {
+    return const_reverse_iterator(begin());
+  }
+  const_reverse_iterator crbegin() const {
+    return const_reverse_iterator(end());
+  }
+  const_reverse_iterator crend() const {
+    return const_reverse_iterator(begin());
+  }
+
+  /// capacity
+  size_t size() const { return length_; }
+  size_t length() const { return length_; }
+  size_t max_size() const { return length_; }
+  bool empty() const { return length_ == 0; }
+
+  /// element access
+  const char* data() const { return data_; }
+
+  /// string operations
+  int compare(string_ref x) const {
+    size_t min_size = length_ < x.length_ ? length_ : x.length_;
+    int r = memcmp(data_, x.data_, min_size);
+    if (r < 0) return -1;
+    if (r > 0) return 1;
+    if (length_ < x.length_) return -1;
+    if (length_ > x.length_) return 1;
+    return 0;
+  }
+
+  bool starts_with(string_ref x) const {
+    return length_ >= x.length_ && (memcmp(data_, x.data_, x.length_) == 0);
+  }
+
+  bool ends_with(string_ref x) const {
+    return length_ >= x.length_ &&
+           (memcmp(data_ + (length_ - x.length_), x.data_, x.length_) == 0);
+  }
+
+  size_t find(string_ref s) const {
+    auto it = std::search(cbegin(), cend(), s.cbegin(), s.cend());
+    return it == cend() ? npos : std::distance(cbegin(), it);
+  }
+
+  size_t find(char c) const {
+    auto it = std::find(cbegin(), cend(), c);
+    return it == cend() ? npos : std::distance(cbegin(), it);
+  }
+
+  string_ref substr(size_t pos, size_t n = npos) const {
+    if (pos > length_) pos = length_;
+    if (n > (length_ - pos)) n = length_ - pos;
+    return string_ref(data_ + pos, n);
+  }
+
+ private:
+  const char* data_;
+  size_t length_;
+};
+
+/// Comparison operators
+inline bool operator==(string_ref x, string_ref y) { return x.compare(y) == 0; }
+inline bool operator!=(string_ref x, string_ref y) { return x.compare(y) != 0; }
+inline bool operator<(string_ref x, string_ref y) { return x.compare(y) < 0; }
+inline bool operator<=(string_ref x, string_ref y) { return x.compare(y) <= 0; }
+inline bool operator>(string_ref x, string_ref y) { return x.compare(y) > 0; }
+inline bool operator>=(string_ref x, string_ref y) { return x.compare(y) >= 0; }
+
+inline std::ostream& operator<<(std::ostream& out, const string_ref& string) {
+  return out << grpc::string(string.begin(), string.end());
+}
+
+}  // namespace grpc
+
+#endif  // GRPCPP_IMPL_CODEGEN_STRING_REF_H