upload android base code part3

android/art/runtime/base/to_str.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * 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 ART_RUNTIME_BASE_TO_STR_H_
+#define ART_RUNTIME_BASE_TO_STR_H_
+
+#include <sstream>
+
+namespace art {
+
+// Helps you use operator<< in a const char*-like context such as our various 'F' methods with
+// format strings.
+template<typename T>
+class ToStr {
+ public:
+  explicit ToStr(const T& value) {
+    std::ostringstream os;
+    os << value;
+    s_ = os.str();
+  }
+
+  const char* c_str() const {
+    return s_.c_str();
+  }
+
+  const std::string& str() const {
+    return s_;
+  }
+
+ private:
+  std::string s_;
+  DISALLOW_COPY_AND_ASSIGN(ToStr);
+};
+
+}  // namespace art
+
+#endif  // ART_RUNTIME_BASE_TO_STR_H_