Move ICU headers part 1

public/common/unicode/stringpiece.h

-// Copyright (C) 2010, International Business Machines
-// Corporation and others. All Rights Reserved.
-//
-// Copyright 2001 and onwards Google Inc.
-// Author: Sanjay Ghemawat
-
-// This code is a contribution of Google code, and the style used here is
-// a compromise between the original Google code and the ICU coding guidelines.
-// For example, data types are ICU-ified (size_t,int->int32_t),
-// and API comments doxygen-ified, but function names and behavior are
-// as in the original, if possible.
-// Assertion-style error handling, not available in ICU, was changed to
-// parameter "pinning" similar to UnicodeString.
-//
-// In addition, this is only a partial port of the original Google code,
-// limited to what was needed so far. The (nearly) complete original code
-// is in the ICU svn repository at icuhtml/trunk/design/strings/contrib
-// (see ICU ticket 6765, r25517).
-
-#ifndef __STRINGPIECE_H__
-#define __STRINGPIECE_H__
-
-/**
- * \file 
- * \brief C++ API: StringPiece: Read-only byte string wrapper class.
- */
-
-#include "unicode/utypes.h"
-#include "unicode/uobject.h"
-#include "unicode/std_string.h"
-
-// Arghh!  I wish C++ literals were "string".
-
-U_NAMESPACE_BEGIN
-
-/**
- * A string-like object that points to a sized piece of memory.
- *
- * We provide non-explicit singleton constructors so users can pass
- * in a "const char*" or a "string" wherever a "StringPiece" is
- * expected.
- *
- * Functions or methods may use const StringPiece& parameters to accept either
- * a "const char*" or a "string" value that will be implicitly converted to
- * a StringPiece.
- *
- * Systematic usage of StringPiece is encouraged as it will reduce unnecessary
- * conversions from "const char*" to "string" and back again.
- *
- * @stable ICU 4.2
- */
-class U_COMMON_API StringPiece : public UMemory {
- private:
-  const char*   ptr_;
-  int32_t       length_;
-
- public:
-  /**
-   * Default constructor, creates an empty StringPiece.
-   * @stable ICU 4.2
-   */
-  StringPiece() : ptr_(NULL), length_(0) { }
-  /**
-   * Constructs from a NUL-terminated const char * pointer.
-   * @param str a NUL-terminated const char * pointer
-   * @stable ICU 4.2
-   */
-  StringPiece(const char* str);
-#if U_HAVE_STD_STRING
-  /**
-   * Constructs from a std::string.
-   * @stable ICU 4.2
-   */
-  StringPiece(const U_STD_NSQ string& str)
-    : ptr_(str.data()), length_(static_cast<int32_t>(str.size())) { }
-#endif
-  /**
-   * Constructs from a const char * pointer and a specified length.
-   * @param offset a const char * pointer (need not be terminated)
-   * @param len the length of the string; must be non-negative
-   * @stable ICU 4.2
-   */
-  StringPiece(const char* offset, int32_t len) : ptr_(offset), length_(len) { }
-  /**
-   * Substring of another StringPiece.
-   * @param x the other StringPiece
-   * @param pos start position in x; must be non-negative and <= x.length().
-   * @stable ICU 4.2
-   */
-  StringPiece(const StringPiece& x, int32_t pos);
-  /**
-   * Substring of another StringPiece.
-   * @param x the other StringPiece
-   * @param pos start position in x; must be non-negative and <= x.length().
-   * @param len length of the substring;
-   *            must be non-negative and will be pinned to at most x.length() - pos.
-   * @stable ICU 4.2
-   */
-  StringPiece(const StringPiece& x, int32_t pos, int32_t len);
-
-  /**
-   * Returns the string pointer. May be NULL if it is empty.
-   *
-   * data() may return a pointer to a buffer with embedded NULs, and the
-   * returned buffer may or may not be null terminated.  Therefore it is
-   * typically a mistake to pass data() to a routine that expects a NUL
-   * terminated string.
-   * @return the string pointer
-   * @stable ICU 4.2
-   */
-  const char* data() const { return ptr_; }
-  /**
-   * Returns the string length. Same as length().
-   * @return the string length
-   * @stable ICU 4.2
-   */
-  int32_t size() const { return length_; }
-  /**
-   * Returns the string length. Same as size().
-   * @return the string length
-   * @stable ICU 4.2
-   */
-  int32_t length() const { return length_; }
-  /**
-   * Returns whether the string is empty.
-   * @return TRUE if the string is empty
-   * @stable ICU 4.2
-   */
-  UBool empty() const { return length_ == 0; }
-
-  /**
-   * Sets to an empty string.
-   * @stable ICU 4.2
-   */
-  void clear() { ptr_ = NULL; length_ = 0; }
-
-  /**
-   * Reset the stringpiece to refer to new data.
-   * @param data pointer the new string data.  Need not be nul terminated.
-   * @param len the length of the new data
-   * @internal
-   */
-  void set(const char* data, int32_t len) { ptr_ = data; length_ = len; }
-
-  /**
-   * Reset the stringpiece to refer to new data.
-   * @param str a pointer to a NUL-terminated string. 
-   * @internal
-   */
-  void set(const char* str);
-
-  /**
-   * Removes the first n string units.
-   * @param n prefix length, must be non-negative and <=length()
-   * @stable ICU 4.2
-   */
-  void remove_prefix(int32_t n) {
-    if (n >= 0) {
-      if (n > length_) {
-        n = length_;
-      }
-      ptr_ += n;
-      length_ -= n;
-    }
-  }
-
-  /**
-   * Removes the last n string units.
-   * @param n suffix length, must be non-negative and <=length()
-   * @stable ICU 4.2
-   */
-  void remove_suffix(int32_t n) {
-    if (n >= 0) {
-      if (n <= length_) {
-        length_ -= n;
-      } else {
-        length_ = 0;
-      }
-    }
-  }
-
-  /**
-   * Maximum integer, used as a default value for substring methods.
-   * @stable ICU 4.2
-   */
-  static const int32_t npos = 0x7fffffff;
-
-  /**
-   * Returns a substring of this StringPiece.
-   * @param pos start position; must be non-negative and <= length().
-   * @param len length of the substring;
-   *            must be non-negative and will be pinned to at most length() - pos.
-   * @return the substring StringPiece
-   * @stable ICU 4.2
-   */
-  StringPiece substr(int32_t pos, int32_t len = npos) const {
-    return StringPiece(*this, pos, len);
-  }
-};
-
-/**
- * Global operator == for StringPiece
- * @param x The first StringPiece to compare.
- * @param y The second StringPiece to compare.
- * @return TRUE if the string data is equal
- * @internal
- */
-U_EXPORT UBool U_EXPORT2 
-operator==(const StringPiece& x, const StringPiece& y);
-
-/**
- * Global operator != for StringPiece
- * @param x The first StringPiece to compare.
- * @param y The second StringPiece to compare.
- * @return TRUE if the string data is not equal
- * @internal
- */
-inline UBool operator!=(const StringPiece& x, const StringPiece& y) {
-  return !(x == y);
-}
-
-U_NAMESPACE_END
-
-#endif  // __STRINGPIECE_H__