/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you 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 .
 */

/*
 * This file is part of LibreOffice published API.
 */

#ifndef INCLUDED_RTL_STRING_HXX
#define INCLUDED_RTL_STRING_HXX

#include "sal/config.h"

#include <cassert>
#include <cstddef>
#include <cstdlib>
#include <limits>
#include <new>
#include <ostream>
#include <utility>
#include <string.h>

#if defined LIBO_INTERNAL_ONLY
#include <string_view>
#include <type_traits>
#endif

#include "rtl/textenc.h"
#include "rtl/string.h"
#include "rtl/stringutils.hxx"

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
#include "config_global.h"
#include "rtl/stringconcat.hxx"
#endif

#ifdef RTL_STRING_UNITTEST
extern bool rtl_string_unittest_const_literal;
extern bool rtl_string_unittest_const_literal_function;
#endif

// The unittest uses slightly different code to help check that the proper
// calls are made. The class is put into a different namespace to make
// sure the compiler generates a different (if generating also non-inline)
// copy of the function and does not merge them together. The class
// is "brought" into the proper rtl namespace by a typedef below.
#ifdef RTL_STRING_UNITTEST
#define rtl rtlunittest
#endif

namespace rtl
{

/// @cond INTERNAL
#ifdef RTL_STRING_UNITTEST
#undef rtl
// helper macro to make functions appear more readable
#define RTL_STRING_CONST_FUNCTION rtl_string_unittest_const_literal_function = true;
#else
#define RTL_STRING_CONST_FUNCTION
#endif
/// @endcond

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
/**
A wrapper dressing a string literal as a static-refcount rtl_String.

This class is not part of public API and is meant to be used only in LibreOffice code.
@since LibreOffice 4.0
*/
template<std::size_t N> class SAL_WARN_UNUSED OStringLiteral {
    static_assert(N != 0);
    static_assert(N - 1 <= std::numeric_limits<sal_Int32>::max(), "literal too long");
    friend class OString;

public:
#if HAVE_CPP_CONSTEVAL
    consteval
#else
    constexpr
#endif
    OStringLiteral(char const (&literal)[N]) {
        assertLayout();
        assert(literal[N - 1] == '\0');
        //TODO: Use C++20 constexpr std::copy_n (P0202R3):
        for (std::size_t i = 0; i != N; ++i) {
            more.buffer[i] = literal[i];
        }
    }

#if defined __cpp_char8_t
#if HAVE_CPP_CONSTEVAL
    consteval
#else
    constexpr
#endif
    explicit OStringLiteral(char8_t const (&literal)[N]) {
        assertLayout();
        assert(literal[N - 1] == '\0');
        //TODO: Use C++20 constexpr std::copy_n (P0202R3):
        for (std::size_t i = 0; i != N; ++i) {
            more.buffer[i] = literal[i];
        }
    }
#endif

    constexpr sal_Int32 getLength() const { return more.length; }

    constexpr char const * getStr() const SAL_RETURNS_NONNULL { return more.buffer; }

    constexpr operator std::string_view() const { return {more.buffer, sal_uInt32(more.length)}; }

private:
    static constexpr void assertLayout() {
        // These static_asserts verifying the layout compatibility with rtl_String cannot be class
        // member declarations, as offsetof requires a complete type, so defer them to here:
        static_assert(std::is_standard_layout_v<OStringLiteral>);
        static_assert(offsetof(OStringLiteral, str.refCount) == offsetof(OStringLiteral, more.refCount));
        static_assert(offsetof(OStringLiteral, str.length) == offsetof(OStringLiteral, more.length));
        static_assert(offsetof(OStringLiteral, str.buffer) == offsetof(OStringLiteral, more.buffer));
    }

    struct Data {
        Data() = default;

        oslInterlockedCount refCount = 0x40000000; // SAL_STRING_STATIC_FLAG (sal/rtl/strimp.hxx)
        sal_Int32 length = N - 1;
        char buffer[N] = {}; //TODO: drop initialization for C++20 (P1331R2)
    };

    union {
        rtl_String str;
        Data more = {};
    };
};
#endif

/* ======================================================================= */

/**
  This String class provide base functionality for C++ like 8-Bit
  character array handling. The advantage of this class is, that it
  handle all the memory management for you - and it do it
  more efficient. If you assign a string to another string, the
  data of both strings are shared (without any copy operation or
  memory allocation) as long as you do not change the string. This class
  stores also the length of the string, so that many operations are
  faster as the C-str-functions.

  This class provides only readonly string handling. So you could create
  a string and you could only query the content from this string.
  It provides also functionality to change the string, but this results
  in every case in a new string instance (in the most cases with an
  memory allocation). You don't have functionality to change the
  content of the string. If you want to change the string content, then
  you should use the OStringBuffer class, which provides these
  functionalities and avoid too much memory allocation.

  The design of this class is similar to the string classes in Java
  and so more people should have fewer understanding problems when they
  use this class.
*/

class SAL_WARN_UNUSED SAL_DLLPUBLIC_RTTI OString
{
public:
    /// @cond INTERNAL
    rtl_String * pData;
    /// @endcond

    /**
      New string containing no characters.
    */
    OString()
    {
        pData = NULL;
        rtl_string_new( &pData );
    }

    /**
      New string from OString.

      @param    str         an OString.
    */
    OString( const OString & str )
    {
        pData = str.pData;
        rtl_string_acquire( pData );
    }

#if defined LIBO_INTERNAL_ONLY
    /**
      Move constructor.

      @param    str         an OString.
      @since LibreOffice 5.2
    */
    OString( OString && str ) noexcept
    {
        pData = str.pData;
        str.pData = nullptr;
        rtl_string_new( &str.pData );
    }
#endif

    /**
      New string from OString data.

      @param    str         an OString data.
    */
    OString( rtl_String * str )
    {
        pData = str;
        rtl_string_acquire( pData );
    }

    /** New string from OString data without acquiring it.  Takeover of ownership.

        The SAL_NO_ACQUIRE dummy parameter is only there to distinguish this
        from other constructors.

      @param    str         an OString data.
    */
    OString( rtl_String * str, __sal_NoAcquire )
    {
        pData = str;
    }

    /**
      New string from a single character.

      @param    value       a character.
    */
    explicit OString( char value )
        : pData (NULL)
    {
        rtl_string_newFromStr_WithLength( &pData, &value, 1 );
    }

#if defined LIBO_INTERNAL_ONLY && !defined RTL_STRING_UNITTEST_CONCAT
    // Catch inadvertent conversions to the above ctor (e.g., from sal_[u]Int8, aka [un]signed
    // char):
    OString(int) = delete;
#endif

    /**
      New string from a character buffer array.

      Note: The argument type is always either char* or const char*. The template is
      used only for technical reasons, as is the second argument.

      @param    value       a NULL-terminated character array.
    */
    template< typename T >
    OString( const T& value, typename libreoffice_internal::CharPtrDetector< T, libreoffice_internal::Dummy >::Type = libreoffice_internal::Dummy() )
    {
        pData = NULL;
        rtl_string_newFromStr( &pData, value );
    }

    template< typename T >
    OString( T& value, typename libreoffice_internal::NonConstCharArrayDetector< T, libreoffice_internal::Dummy >::Type = libreoffice_internal::Dummy() )
    {
        pData = NULL;
        rtl_string_newFromStr( &pData, value );
    }

    /**
      New string from a string literal.

      If there are any embedded \0's in the string literal, the result is undefined.
      Use the overload that explicitly accepts length.

      @since LibreOffice 3.6

      @param    literal       a string literal
    */
    template< typename T >
    OString( T& literal, typename libreoffice_internal::ConstCharArrayDetector< T, libreoffice_internal::Dummy >::Type = libreoffice_internal::Dummy() )
    {
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        pData = NULL;
        if (libreoffice_internal::ConstCharArrayDetector<T>::length == 0) {
            rtl_string_new(&pData);
        } else {
            rtl_string_newFromLiteral(
                &pData,
                libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                    literal),
                libreoffice_internal::ConstCharArrayDetector<T>::length, 0);
        }
#ifdef RTL_STRING_UNITTEST
        rtl_string_unittest_const_literal = true;
#endif
    }

    /**
      New string from a character buffer array.

      @param    value       a character array.
      @param    length      the number of character which should be copied.
                            The character array length must be greater or
                            equal than this value.
    */
    OString( const char * value, sal_Int32 length )
    {
        pData = NULL;
        rtl_string_newFromStr_WithLength( &pData, value, length );
    }

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
    /// @cond INTERNAL
    /**
      New string from an 8-Bit string literal.

      @since LibreOffice 7.1
    */
    template<std::size_t N> constexpr OString(OStringLiteral<N> const & literal):
        pData(const_cast<rtl_String *>(&literal.str)) {}
    template<std::size_t N> OString(OStringLiteral<N> &&) = delete;
    /// @endcond
#endif

#if defined LIBO_INTERNAL_ONLY
    explicit OString(std::string_view sv) {
        if (sv.size() > sal_uInt32(std::numeric_limits<sal_Int32>::max())) {
            throw std::bad_alloc();
        }
        pData = nullptr;
        rtl_string_newFromStr_WithLength(&pData, sv.data(), sv.size());
    }
#endif

    /**
      New string from a Unicode character buffer array.

      @param    value           a Unicode character array.
      @param    length          the number of character which should be converted.
                                The Unicode character array length must be
                                greater or equal than this value.
      @param    encoding        the text encoding in which the Unicode character
                                sequence should be converted.
      @param    convertFlags    flags which controls the conversion.
                                see RTL_UNICODETOTEXT_FLAGS_...

      @exception std::bad_alloc is thrown if an out-of-memory condition occurs
    */
    OString( const sal_Unicode * value, sal_Int32 length,
             rtl_TextEncoding encoding,
             sal_uInt32 convertFlags = OUSTRING_TO_OSTRING_CVTFLAGS )
    {
        pData = NULL;
        rtl_uString2String( &pData, value, length, encoding, convertFlags );
        if (pData == NULL) {
            throw std::bad_alloc();
        }
    }

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
    /**
     @overload
     @internal
    */
    template< typename T1, typename T2 >
    OString( OStringConcat< T1, T2 >&& c )
    {
        const sal_Int32 l = c.length();
        pData = rtl_string_alloc( l );
        if (l != 0)
        {
            char* end = c.addData( pData->buffer );
            pData->length = l;
            *end = '\0';
        }
    }

    /**
     @overload
     @internal
    */
    template< typename T >
    OString( OStringNumber< T >&& n )
        : OString( n.buf, n.length )
    {}
#endif

#ifdef LIBO_INTERNAL_ONLY
    OString(std::nullptr_t) = delete;
#endif

    /**
      Release the string data.
    */
    ~OString()
    {
        rtl_string_release( pData );
    }

    /**
      Assign a new string.

      @param    str         an OString.
    */
    OString & operator=( const OString & str )
    {
        rtl_string_assign( &pData, str.pData );
        return *this;
    }

#if defined LIBO_INTERNAL_ONLY
    /**
      Move assign a new string.

      @param    str         an OString.
      @since LibreOffice 5.2
    */
    OString & operator=( OString && str ) noexcept
    {
        rtl_string_release( pData );
        pData = str.pData;
        str.pData = nullptr;
        rtl_string_new( &str.pData );
        return *this;
    }
#endif

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, OString& >::Type operator=( T& literal )
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        if (libreoffice_internal::ConstCharArrayDetector<T>::length == 0) {
            rtl_string_new(&pData);
        } else {
            rtl_string_newFromLiteral(
                &pData,
                libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                    literal),
                libreoffice_internal::ConstCharArrayDetector<T>::length, 0);
        }
        return *this;
    }

    /**
      Append a string to this string.

      @param    str         an OString.
    */
    OString & operator+=( const OString & str )
#if defined LIBO_INTERNAL_ONLY
        &
#endif
    {
        rtl_string_newConcat( &pData, pData, str.pData );
        return *this;
    }
#if defined LIBO_INTERNAL_ONLY
    void operator+=(OString const &) && = delete;
#endif

#if defined LIBO_INTERNAL_ONLY
    template<typename T> typename libreoffice_internal::CharPtrDetector<T, OString &>::Type
    operator +=(T const & value) & { return operator +=(std::string_view(value)); }
    template<typename T> typename libreoffice_internal::CharPtrDetector<T, OString &>::Type
    operator +=(T const &) && = delete;

    template<typename T>
    typename libreoffice_internal::NonConstCharArrayDetector<T, OString &>::Type
    operator +=(T & value) & { return operator +=(std::string_view(value)); }
    template<typename T>
    typename libreoffice_internal::NonConstCharArrayDetector<T, OString &>::Type operator +=(T &) &&
        = delete;

    template<typename T> typename libreoffice_internal::ConstCharArrayDetector<T, OString &>::Type
    operator +=(T & literal) & {
        assert(libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        return operator +=(
            std::string_view(
                libreoffice_internal::ConstCharArrayDetector<T>::toPointer(literal),
                libreoffice_internal::ConstCharArrayDetector<T>::length));
    }
    template<typename T> typename libreoffice_internal::ConstCharArrayDetector<T, OString &>::Type
    operator +=(T &) && = delete;

    template<std::size_t N> OString & operator +=(OStringLiteral<N> const & literal) &
    { return operator +=(std::string_view(literal.getStr(), literal.getLength())); }
    template<std::size_t N> void operator +=(OStringLiteral<N> const &) && = delete;

    OString & operator +=(std::string_view sv) & {
        if (sv.empty()) {
            return *this;
        }
        if (sv.size() > sal_uInt32(std::numeric_limits<sal_Int32>::max() - pData->length)) {
            throw std::bad_alloc();
        }
        auto const l = pData->length + sv.size();
        rtl_string_ensureCapacity(&pData, l);
        *addDataHelper(pData->buffer + pData->length, sv.data(), sv.size()) = '\0';
        pData->length = l;
        return *this;
    }
    void operator +=(std::string_view) && = delete;
#endif

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
    /**
     @overload
     @internal
    */
    template< typename T1, typename T2 >
    OString& operator+=( OStringConcat< T1, T2 >&& c ) & {
        sal_Int32 l = c.length();
        if( l == 0 )
            return *this;
        l += pData->length;
        rtl_string_ensureCapacity( &pData, l );
        char* end = c.addData( pData->buffer + pData->length );
        *end = '\0';
        pData->length = l;
        return *this;
    }
    template<typename T1, typename T2> void operator +=(
        OStringConcat<T1, T2> &&) && = delete;

    /**
     @overload
     @internal
    */
    template< typename T >
    OString& operator+=( OStringNumber< T >&& n ) & {
        return operator +=(std::string_view(n.buf, n.length));
    }
    template<typename T> void operator +=(
        OStringNumber<T> &&) && = delete;
#endif

    /**
      Clears the string, i.e, makes a zero-character string
      @since LibreOffice 4.4
    */
    void clear()
    {
        rtl_string_new( &pData );
    }

    /**
      Returns the length of this string.

      The length is equal to the number of characters in this string.

      @return   the length of the sequence of characters represented by this
                object.
    */
    sal_Int32 getLength() const { return pData->length; }

    /**
      Checks if a string is empty.

      @return   true if the string is empty;
                false, otherwise.

      @since LibreOffice 3.4
    */
    bool isEmpty() const
    {
        return pData->length == 0;
    }

    /**
      Returns a pointer to the characters of this string.

      <p>The returned pointer is guaranteed to point to a null-terminated byte
      string.  But note that this string object may contain embedded null
      characters, which will thus also be embedded in the returned
      null-terminated byte string.</p>

      @return a pointer to a null-terminated byte string representing the
      characters of this string object.
    */
    const char * getStr() const SAL_RETURNS_NONNULL { return pData->buffer; }

    /**
      Access to individual characters.

      @param index must be non-negative and less than length.

      @return the character at the given index.

      @since LibreOffice 3.5
    */
    char operator [](sal_Int32 index) const {
        // silence spurious -Werror=strict-overflow warnings from GCC 4.8.2
        assert(index >= 0 && static_cast<sal_uInt32>(index) < static_cast<sal_uInt32>(getLength()));
        return getStr()[index];
    }

    /**
      Compares two strings.

      The comparison is based on the numeric value of each character in
      the strings and return a value indicating their relationship.
      This function can't be used for language specific sorting.

      @param    str         the object to be compared.
      @return   0 - if both strings are equal
                < 0 - if this string is less than the string argument
                > 0 - if this string is greater than the string argument
    */
    sal_Int32 compareTo( const OString & str ) const
    {
        return rtl_str_compare_WithLength( pData->buffer, pData->length,
                                           str.pData->buffer, str.pData->length );
    }

    /**
      Compares two strings with an maximum count of characters.

      The comparison is based on the numeric value of each character in
      the strings and return a value indicating their relationship.
      This function can't be used for language specific sorting.

      @param    rObj        the object to be compared.
      @param    maxLength   the maximum count of characters to be compared.
      @return   0 - if both strings are equal
                < 0 - if this string is less than the string argument
                > 0 - if this string is greater than the string argument
    */
    sal_Int32 compareTo( const OString & rObj, sal_Int32 maxLength ) const
    {
        return rtl_str_shortenedCompare_WithLength( pData->buffer, pData->length,
                                                    rObj.pData->buffer, rObj.pData->length, maxLength );
    }

    /**
      Compares two strings in reverse order.

      The comparison is based on the numeric value of each character in
      the strings and return a value indicating their relationship.
      This function can't be used for language specific sorting.

      @param    str         the object to be compared.
      @return   0 - if both strings are equal
                < 0 - if this string is less than the string argument
                > 0 - if this string is greater than the string argument
    */
    sal_Int32 reverseCompareTo( const OString & str ) const
    {
        return rtl_str_reverseCompare_WithLength( pData->buffer, pData->length,
                                                  str.pData->buffer, str.pData->length );
    }

    /**
      Perform a comparison of two strings.

      The result is true if and only if second string
      represents the same sequence of characters as the first string.
      This function can't be used for language specific comparison.

      @param    str         the object to be compared.
      @return   true if the strings are equal;
                false, otherwise.
    */
    bool equals( const OString & str ) const
    {
        if ( pData->length != str.pData->length )
            return false;
        if ( pData == str.pData )
            return true;
        return rtl_str_reverseCompare_WithLength( pData->buffer, pData->length,
                                                  str.pData->buffer, str.pData->length ) == 0;
    }

    /**
      Perform a comparison of two strings.

      The result is true if and only if second string
      represents the same sequence of characters as the first string.
      The ASCII string must be NULL-terminated and must be greater or
      equal as length.
      This function can't be used for language specific comparison.


      @param    value       a character array.
      @param    length      the length of the character array.
      @return   true if the strings are equal;
                false, otherwise.
    */
    bool equalsL( const char* value, sal_Int32 length ) const
    {
        if ( pData->length != length )
            return false;

        return rtl_str_reverseCompare_WithLength( pData->buffer, pData->length,
                                                  value, length ) == 0;
    }

    /**
      Perform an ASCII lowercase comparison of two strings.

      The result is true if and only if second string
      represents the same sequence of characters as the first string,
      ignoring the case.
      Character values between 65 and 90 (ASCII A-Z) are interpreted as
      values between 97 and 122 (ASCII a-z).
      This function can't be used for language specific comparison.

      @param    str         the object to be compared.
      @return   true if the strings are equal;
                false, otherwise.
    */
#if defined LIBO_INTERNAL_ONLY
    bool equalsIgnoreAsciiCase( std::string_view str ) const
    {
        if ( sal_uInt32(pData->length) != str.size() )
            return false;
        if ( pData->buffer == str.data() )
            return true;
        return rtl_str_compareIgnoreAsciiCase_WithLength( pData->buffer, pData->length,
                                                          str.data(), str.size() ) == 0;
    }
#else
    bool equalsIgnoreAsciiCase( const OString & str ) const
    {
        if ( pData->length != str.pData->length )
            return false;
        if ( pData == str.pData )
            return true;
        return rtl_str_compareIgnoreAsciiCase_WithLength( pData->buffer, pData->length,
                                                          str.pData->buffer, str.pData->length ) == 0;
    }
#endif

    /**
      Perform an ASCII lowercase comparison of two strings.

      The result is true if and only if second string
      represents the same sequence of characters as the first string,
      ignoring the case.
      Character values between 65 and 90 (ASCII A-Z) are interpreted as
      values between 97 and 122 (ASCII a-z).
      Since this method is optimized for performance, the ASCII character
      values are not converted in any way. The caller has to make sure that
      all ASCII characters are in the allowed range between 0 and
      127. The ASCII string must be NULL-terminated.
      This function can't be used for language specific comparison.

      Note: The argument type is always either char* or const char*, the return type is bool.
      The template is used only for technical reasons.

      @param    asciiStr        the 8-Bit ASCII character string to be compared.
      @return   true if the strings are equal;
                false, otherwise.
    */
    template< typename T >
    typename libreoffice_internal::CharPtrDetector< T, bool >::Type equalsIgnoreAsciiCase( const T& asciiStr ) const
    {
        return rtl_str_compareIgnoreAsciiCase( pData->buffer, asciiStr ) == 0;
    }

    template< typename T >
    typename libreoffice_internal::NonConstCharArrayDetector< T, bool >::Type equalsIgnoreAsciiCase( T& asciiStr ) const
    {
        return rtl_str_compareIgnoreAsciiCase( pData->buffer, asciiStr ) == 0;
    }

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type  equalsIgnoreAsciiCase( T& literal ) const
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        return
            (pData->length
             == libreoffice_internal::ConstCharArrayDetector<T>::length)
            && (rtl_str_compareIgnoreAsciiCase_WithLength(
                    pData->buffer, pData->length,
                    libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                        literal),
                    libreoffice_internal::ConstCharArrayDetector<T>::length)
                == 0);
    }

    /**
      Perform an ASCII lowercase comparison of two strings.

      The result is true if and only if second string
      represents the same sequence of characters as the first string,
      ignoring the case.
      Character values between 65 and 90 (ASCII A-Z) are interpreted as
      values between 97 and 122 (ASCII a-z).
      Since this method is optimized for performance, the ASCII character
      values are not converted in any way. The caller has to make sure that
      all ASCII characters are in the allowed range between 0 and
      127. The ASCII string must be greater or equal in length as asciiStrLength.
      This function can't be used for language specific comparison.

      @param    asciiStr        the 8-Bit ASCII character string to be compared.
      @param    asciiStrLength  the length of the ascii string
      @return   true if the strings are equal;
                false, otherwise.
    */
    bool equalsIgnoreAsciiCaseL( const char * asciiStr, sal_Int32 asciiStrLength ) const
    {
        if ( pData->length != asciiStrLength )
            return false;

        return rtl_str_compareIgnoreAsciiCase_WithLength( pData->buffer, pData->length,
                                                          asciiStr, asciiStrLength ) == 0;
    }

    /**
      Match against a substring appearing in this string.

      The result is true if and only if the second string appears as a substring
      of this string, at the given position.
      This function can't be used for language specific comparison.

      @param    str         the object (substring) to be compared.
      @param    fromIndex   the index to start the comparison from.
                            The index must be greater or equal than 0
                            and less or equal as the string length.
      @return   true if str match with the characters in the string
                at the given position;
                false, otherwise.
    */
#if defined LIBO_INTERNAL_ONLY
    bool match( std::string_view str, sal_Int32 fromIndex = 0 ) const
    {
        return rtl_str_shortenedCompare_WithLength( pData->buffer+fromIndex, pData->length-fromIndex,
                                                    str.data(), str.size(), str.size() ) == 0;
    }
#else
    bool match( const OString & str, sal_Int32 fromIndex = 0 ) const
    {
        return rtl_str_shortenedCompare_WithLength( pData->buffer+fromIndex, pData->length-fromIndex,
                                                    str.pData->buffer, str.pData->length, str.pData->length ) == 0;
    }
#endif

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type  match( T& literal, sal_Int32 fromIndex = 0 ) const
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        return
            rtl_str_shortenedCompare_WithLength(
                pData->buffer + fromIndex, pData->length - fromIndex,
                libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                    literal),
                libreoffice_internal::ConstCharArrayDetector<T>::length,
                libreoffice_internal::ConstCharArrayDetector<T>::length)
            == 0;
    }

    /**
      Match against a substring appearing in this string.

      @param str  the substring to be compared; must not be null and must point
      to memory of at least strLength bytes

      @param strLength  the length of the substring; must be non-negative

      @param fromIndex  the index into this string to start the comparison at;
      must be non-negative and not greater than this string's length

      @return true if and only if the given str is contained as a substring of
      this string at the given fromIndex

      @since LibreOffice 3.6
    */
    bool matchL(
        char const * str, sal_Int32 strLength, sal_Int32 fromIndex = 0)
        const
    {
        return rtl_str_shortenedCompare_WithLength(
            pData->buffer + fromIndex, pData->length - fromIndex,
            str, strLength, strLength) == 0;
    }

    // This overload is left undefined, to detect calls of matchL that
    // erroneously use RTL_CONSTASCII_USTRINGPARAM instead of
    // RTL_CONSTASCII_STRINGPARAM (but would lead to ambiguities on 32 bit
    // platforms):
#if SAL_TYPES_SIZEOFLONG == 8
    void matchL(char const *, sal_Int32, rtl_TextEncoding) const;
#endif

    /**
      Match against a substring appearing in this string, ignoring the case of
      ASCII letters.

      The result is true if and only if the second string appears as a substring
      of this string, at the given position.
      Character values between 65 and 90 (ASCII A-Z) are interpreted as
      values between 97 and 122 (ASCII a-z).
      This function can't be used for language specific comparison.

      @param    str         the object (substring) to be compared.
      @param    fromIndex   the index to start the comparison from.
                            The index must be greater or equal than 0
                            and less or equal as the string length.
      @return   true if str match with the characters in the string
                at the given position;
                false, otherwise.
    */
#if defined LIBO_INTERNAL_ONLY
    bool matchIgnoreAsciiCase( std::string_view str, sal_Int32 fromIndex = 0 ) const
    {
        return rtl_str_shortenedCompareIgnoreAsciiCase_WithLength( pData->buffer+fromIndex, pData->length-fromIndex,
                                                                   str.data(), str.size(),
                                                                   str.size() ) == 0;
    }
#else
    bool matchIgnoreAsciiCase( const OString & str, sal_Int32 fromIndex = 0 ) const
    {
        return rtl_str_shortenedCompareIgnoreAsciiCase_WithLength( pData->buffer+fromIndex, pData->length-fromIndex,
                                                                   str.pData->buffer, str.pData->length,
                                                                   str.pData->length ) == 0;
    }
#endif
    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type matchIgnoreAsciiCase( T& literal, sal_Int32 fromIndex = 0 ) const
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        return
            rtl_str_shortenedCompareIgnoreAsciiCase_WithLength(
                pData->buffer+fromIndex, pData->length-fromIndex,
                libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                    literal),
                libreoffice_internal::ConstCharArrayDetector<T>::length,
                libreoffice_internal::ConstCharArrayDetector<T>::length)
            == 0;
    }

    /**
      Check whether this string starts with a given substring.

      @param str the substring to be compared

      @param rest if non-null, and this function returns true, then assign a
      copy of the remainder of this string to *rest. Available since
      LibreOffice 4.2

      @return true if and only if the given str appears as a substring at the
      start of this string

      @since LibreOffice 4.0
    */
#if defined LIBO_INTERNAL_ONLY
    bool startsWith(std::string_view str, OString * rest = NULL) const {
        bool b = match(str);
        if (b && rest != NULL) {
            *rest = copy(str.size());
        }
        return b;
    }
#else
    bool startsWith(OString const & str, OString * rest = NULL) const {
        bool b = match(str);
        if (b && rest != NULL) {
            *rest = copy(str.getLength());
        }
        return b;
    }
#endif

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 4.0
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type startsWith(
        T & literal, OString * rest = NULL) const
    {
        RTL_STRING_CONST_FUNCTION
        bool b = match(literal, 0);
        if (b && rest != NULL) {
            *rest = copy(
                libreoffice_internal::ConstCharArrayDetector<T>::length);
        }
        return b;
    }

    /**
      Check whether this string starts with a given string, ignoring the case of
      ASCII letters.

      Character values between 65 and 90 (ASCII A-Z) are interpreted as
      values between 97 and 122 (ASCII a-z).
      This function can't be used for language specific comparison.

      @param str the substring to be compared

      @param rest if non-null, and this function returns true, then assign a
      copy of the remainder of this string to *rest.

      @return true if and only if the given str appears as a substring at the
      start of this string, ignoring the case of ASCII letters ("A"--"Z" and
      "a"--"z")

      @since LibreOffice 5.1
    */
#if defined LIBO_INTERNAL_ONLY
    bool startsWithIgnoreAsciiCase(std::string_view str, OString * rest = NULL)
        const
    {
        bool b = matchIgnoreAsciiCase(str);
        if (b && rest != NULL) {
            *rest = copy(str.size());
        }
        return b;
    }
#else
    bool startsWithIgnoreAsciiCase(OString const & str, OString * rest = NULL)
        const
    {
        bool b = matchIgnoreAsciiCase(str);
        if (b && rest != NULL) {
            *rest = copy(str.getLength());
        }
        return b;
    }
#endif

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 5.1
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type
    startsWithIgnoreAsciiCase(T & literal, OString * rest = NULL) const
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        bool b = matchIgnoreAsciiCase(literal);
        if (b && rest != NULL) {
            *rest = copy(
                libreoffice_internal::ConstCharArrayDetector<T>::length);
        }
        return b;
    }

    /**
      Check whether this string ends with a given substring.

      @param str the substring to be compared

      @param rest if non-null, and this function returns true, then assign a
      copy of the remainder of this string to *rest. Available since
      LibreOffice 4.2

      @return true if and only if the given str appears as a substring at the
      end of this string

      @since LibreOffice 3.6
    */
#if defined LIBO_INTERNAL_ONLY
    bool endsWith(std::string_view str, OString * rest = NULL) const {
        bool b = str.size() <= sal_uInt32(getLength())
            && match(str, getLength() - str.size());
        if (b && rest != NULL) {
            *rest = copy(0, getLength() - str.size());
        }
        return b;
    }
#else
    bool endsWith(OString const & str, OString * rest = NULL) const {
        bool b = str.getLength() <= getLength()
            && match(str, getLength() - str.getLength());
        if (b && rest != NULL) {
            *rest = copy(0, getLength() - str.getLength());
        }
        return b;
    }
#endif

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type endsWith(
        T & literal, OString * rest = NULL) const
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        bool b
            = (libreoffice_internal::ConstCharArrayDetector<T>::length
               <= sal_uInt32(getLength()))
            && match(
                libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                    literal),
                (getLength()
                 - libreoffice_internal::ConstCharArrayDetector<T>::length));
        if (b && rest != NULL) {
            *rest = copy(
                0,
                (getLength()
                 - libreoffice_internal::ConstCharArrayDetector<T>::length));
        }
        return b;
    }

    /**
      Check whether this string ends with a given substring.

      @param str  the substring to be compared; must not be null and must point
      to memory of at least strLength bytes

      @param strLength  the length of the substring; must be non-negative

      @return true if and only if the given str appears as a substring at the
      end of this string

      @since LibreOffice 3.6
    */
    bool endsWithL(char const * str, sal_Int32 strLength) const {
        return strLength <= getLength()
            && matchL(str, strLength, getLength() - strLength);
    }

    friend bool     operator == ( const OString& rStr1, const OString& rStr2 )
                        { return rStr1.equals(rStr2); }
    friend bool     operator != ( const OString& rStr1,     const OString& rStr2 )
                        { return !(operator == ( rStr1, rStr2 )); }
    friend bool     operator <  ( const OString& rStr1,    const OString& rStr2 )
                        { return rStr1.compareTo( rStr2 ) < 0; }
    friend bool     operator >  ( const OString& rStr1,    const OString& rStr2 )
                        { return rStr1.compareTo( rStr2 ) > 0; }
    friend bool     operator <= ( const OString& rStr1,    const OString& rStr2 )
                        { return rStr1.compareTo( rStr2 ) <= 0; }
    friend bool     operator >= ( const OString& rStr1,    const OString& rStr2 )
                        { return rStr1.compareTo( rStr2 ) >= 0; }

    template< typename T >
    friend typename libreoffice_internal::CharPtrDetector< T, bool >::Type operator==( const OString& rStr1, const T& value )
    {
        return
            rtl_str_compare_WithLength(
                rStr1.getStr(), rStr1.getLength(), value, rtl_str_getLength(value))
            == 0;
    }

    template< typename T >
    friend typename libreoffice_internal::NonConstCharArrayDetector< T, bool >::Type operator==( const OString& rStr1, T& value )
    {
        return
            rtl_str_compare_WithLength(
                rStr1.getStr(), rStr1.getLength(), value, rtl_str_getLength(value))
            == 0;
    }

    template< typename T >
    friend typename libreoffice_internal::CharPtrDetector< T, bool >::Type operator==( const T& value, const OString& rStr2 )
    {
        return
            rtl_str_compare_WithLength(
                value, rtl_str_getLength(value), rStr2.getStr(), rStr2.getLength())
            == 0;
    }

    template< typename T >
    friend typename libreoffice_internal::NonConstCharArrayDetector< T, bool >::Type operator==( T& value, const OString& rStr2 )
    {
        return
            rtl_str_compare_WithLength(
                value, rtl_str_getLength(value), rStr2.getStr(), rStr2.getLength())
            == 0;
    }

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    friend typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type operator==( const OString& rStr, T& literal )
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        return
            (rStr.getLength()
             == libreoffice_internal::ConstCharArrayDetector<T>::length)
            && (rtl_str_compare_WithLength(
                    rStr.pData->buffer, rStr.pData->length,
                    libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                        literal),
                    libreoffice_internal::ConstCharArrayDetector<T>::length)
                == 0);
    }

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    friend typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type operator==( T& literal, const OString& rStr )
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        return
            (rStr.getLength()
             == libreoffice_internal::ConstCharArrayDetector<T>::length)
            && (rtl_str_compare_WithLength(
                    rStr.pData->buffer, rStr.pData->length,
                    libreoffice_internal::ConstCharArrayDetector<T>::toPointer(
                        literal),
                    libreoffice_internal::ConstCharArrayDetector<T>::length)
                == 0);
    }

    template< typename T >
    friend typename libreoffice_internal::CharPtrDetector< T, bool >::Type operator!=( const OString& rStr1, const T& value )
    {
        return !(operator == ( rStr1, value ));
    }

    template< typename T >
    friend typename libreoffice_internal::NonConstCharArrayDetector< T, bool >::Type operator!=( const OString& rStr1, T& value )
    {
        return !(operator == ( rStr1, value ));
    }

    template< typename T >
    friend typename libreoffice_internal::CharPtrDetector< T, bool >::Type operator!=( const T& value,   const OString& rStr2 )
    {
        return !(operator == ( value, rStr2 ));
    }

    template< typename T >
    friend typename libreoffice_internal::NonConstCharArrayDetector< T, bool >::Type operator!=( T& value,   const OString& rStr2 )
    {
        return !(operator == ( value, rStr2 ));
    }

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    friend typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type operator!=( const OString& rStr, T& literal )
    {
        return !( rStr == literal );
    }

    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    friend typename libreoffice_internal::ConstCharArrayDetector< T, bool >::Type operator!=( T& literal, const OString& rStr )
    {
        return !( literal == rStr );
    }

    /**
      Returns a hashcode for this string.

      @return   a hash code value for this object.

      @see rtl::OStringHash for convenient use of std::unordered_map
    */
    sal_Int32 hashCode() const
    {
        return rtl_str_hashCode_WithLength( pData->buffer, pData->length );
    }

    /**
      Returns the index within this string of the first occurrence of the
      specified character, starting the search at the specified index.

      @param    ch          character to be located.
      @param    fromIndex   the index to start the search from.
                            The index must be greater or equal than 0
                            and less or equal as the string length.
      @return   the index of the first occurrence of the character in the
                character sequence represented by this string that is
                greater than or equal to fromIndex, or
                -1 if the character does not occur.
    */
    sal_Int32 indexOf( char ch, sal_Int32 fromIndex = 0 ) const
    {
        sal_Int32 ret = rtl_str_indexOfChar_WithLength( pData->buffer+fromIndex, pData->length-fromIndex, ch );
        return (ret < 0 ? ret : ret+fromIndex);
    }

    /**
      Returns the index within this string of the last occurrence of the
      specified character, searching backward starting at the end.

      @param    ch          character to be located.
      @return   the index of the last occurrence of the character in the
                character sequence represented by this string, or
                -1 if the character does not occur.
    */
    sal_Int32 lastIndexOf( char ch ) const
    {
        return rtl_str_lastIndexOfChar_WithLength( pData->buffer, pData->length, ch );
    }

    /**
      Returns the index within this string of the last occurrence of the
      specified character, searching backward starting before the specified
      index.

      @param    ch          character to be located.
      @param    fromIndex   the index before which to start the search.
      @return   the index of the last occurrence of the character in the
                character sequence represented by this string that
                is less than fromIndex, or -1
                if the character does not occur before that point.
    */
    sal_Int32 lastIndexOf( char ch, sal_Int32 fromIndex ) const
    {
        return rtl_str_lastIndexOfChar_WithLength( pData->buffer, fromIndex, ch );
    }

    /**
      Returns the index within this string of the first occurrence of the
      specified substring, starting at the specified index.

      If str doesn't include any character, always -1 is
      returned. This is also the case, if both strings are empty.

      @param    str         the substring to search for.
      @param    fromIndex   the index to start the search from.
      @return   If the string argument occurs one or more times as a substring
                within this string at the starting index, then the index
                of the first character of the first such substring is
                returned. If it does not occur as a substring starting
                at fromIndex or beyond, -1 is returned.
    */
#if defined LIBO_INTERNAL_ONLY
    sal_Int32 indexOf( std::string_view str, sal_Int32 fromIndex = 0 ) const
    {
        sal_Int32 ret = rtl_str_indexOfStr_WithLength( pData->buffer+fromIndex, pData->length-fromIndex,
                                                       str.data(), str.size() );
        return (ret < 0 ? ret : ret+fromIndex);
    }
#else
    sal_Int32 indexOf( const OString & str, sal_Int32 fromIndex = 0 ) const
    {
        sal_Int32 ret = rtl_str_indexOfStr_WithLength( pData->buffer+fromIndex, pData->length-fromIndex,
                                                       str.pData->buffer, str.pData->length );
        return (ret < 0 ? ret : ret+fromIndex);
    }
#endif
    /**
     @overload
     This function accepts an ASCII string literal as its argument.
     @since LibreOffice 3.6
    */
    template< typename T >
    typename libreoffice_internal::ConstCharArrayDetector< T, sal_Int32 >::Type indexOf( T& literal, sal_Int32 fromIndex = 0 ) const
    {
        RTL_STRING_CONST_FUNCTION
        assert(
            libreoffice_internal::ConstCharArrayDetector<T>::isValid(literal));
        sal_Int32 n = rtl_str_indexOfStr_WithLength(
            pData->buffer + fromIndex, pData->length - fromIndex,
            libreoffice_internal::ConstCharArrayDetector<T>::toPointer(literal),
            libreoffice_internal::ConstCharArrayDetector<T>::length);
        return n < 0 ? n : n + fromIndex;
    }

    /**
      Returns the index within this string of the first occurrence of the
      specified substring, starting at the specified index.

      If str doesn't include any character, always -1 is
      returned. This is also the case, if both strings are empty.

      @param    str         the substring to search for.
      @param    len         the length of the substring.
      @param    fromIndex   the index to start the search from.
      @return   If the string argument occurs one or more times as a substring
                within this string at the starting index, then the index
                of the first character of the first such substring is
                returned. If it does not occur as a substring starting
                at fromIndex or beyond, -1 is returned.

      @since LibreOffice 3.6
    */
    sal_Int32 indexOfL(char const * str, sal_Int32 len, sal_Int32 fromIndex = 0)
        const
    {
        sal_Int32 n = rtl_str_indexOfStr_WithLength(
            pData->buffer + fromIndex, pData->length - fromIndex, str, len);
        return n < 0 ? n : n + fromIndex;
    }

    // This overload is left undefined, to detect calls of indexOfL that
    // erroneously use RTL_CONSTASCII_USTRINGPARAM instead of
    // RTL_CONSTASCII_STRINGPARAM (but would lead to ambiguities on 32 bit
    // platforms):
#if SAL_TYPES_SIZEOFLONG == 8
    void indexOfL(char const *, sal_Int32, rtl_TextEncoding) const;
#endif

    /**
      Returns the index within this string of the last occurrence of
      the specified substring, searching backward starting at the end.

      The returned index indicates the starting index of the substring
      in this string.
      If str doesn't include any character, always -1 is
      returned. This is also the case, if both strings are empty.

      @param    str         the substring to search for.
      @return   If the string argument occurs one or more times as a substring
                within this string, then the index of the first character of
                the last such substring is returned. If it does not occur as
                a substring, -1 is returned.
    */
#if defined LIBO_INTERNAL_ONLY
    sal_Int32 lastIndexOf( std::string_view str ) const
    {
        return rtl_str_lastIndexOfStr_WithLength( pData->buffer, pData->length,
                                                  str.data(), str.size() );
    }
#else
    sal_Int32 lastIndexOf( const OString & str ) const
    {
        return rtl_str_lastIndexOfStr_WithLength( pData->buffer, pData->length,
                                                  str.pData->buffer, str.pData->length );
    }
#endif

    /**
      Returns the index within this string of the last occurrence of
      the specified substring, searching backward starting before the specified
      index.

      The returned index indicates the starting index of the substring
      in this string.
      If str doesn't include any character, always -1 is
      returned. This is also the case, if both strings are empty.

      @param    str         the substring to search for.
      @param    fromIndex   the index before which to start the search.
      @return   If the string argument occurs one or more times as a substring
                within this string before the starting index, then the index
                of the first character of the last such substring is
                returned. Otherwise, -1 is returned.
    */
#if defined LIBO_INTERNAL_ONLY
    sal_Int32 lastIndexOf( std::string_view str, sal_Int32 fromIndex ) const
    {
        return rtl_str_lastIndexOfStr_WithLength( pData->buffer, fromIndex,
                                                  str.data(), str.size() );
    }
#else
    sal_Int32 lastIndexOf( const OString & str, sal_Int32 fromIndex ) const
    {
        return rtl_str_lastIndexOfStr_WithLength( pData->buffer, fromIndex,
                                                  str.pData->buffer, str.pData->length );
    }
#endif

    /**
      Returns a new string that is a substring of this string.

      The substring begins at the specified beginIndex. If
      beginIndex is negative or be greater than the length of
      this string, behaviour is undefined.

      @param     beginIndex   the beginning index, inclusive.
      @return    the specified substring.
    */
    SAL_WARN_UNUSED_RESULT OString copy( sal_Int32 beginIndex ) const
    {
        return copy(beginIndex, getLength() - beginIndex);
    }

    /**
      Returns a new string that is a substring of this string.

      The substring begins at the specified beginIndex and contains count
      characters.  If either beginIndex or count are negative,
      or beginIndex + count are greater than the length of this string
      then behaviour is undefined.

      @param     beginIndex   the beginning index, inclusive.
      @param     count        the number of characters.
      @return    the specified substring.
    */
    SAL_WARN_UNUSED_RESULT OString copy( sal_Int32 beginIndex, sal_Int32 count ) const
    {
        rtl_String *pNew = NULL;
        rtl_string_newFromSubString( &pNew, pData, beginIndex, count );
        return OString( pNew, SAL_NO_ACQUIRE );
    }

#if defined LIBO_INTERNAL_ONLY
    /**
      Returns a std::string_view that is a view of a substring of this string.

      The substring begins at the specified beginIndex. If
      beginIndex is negative or be greater than the length of
      this string, behaviour is undefined.

      @param     beginIndex   the beginning index, inclusive.
      @return    the specified substring.
    */
    SAL_WARN_UNUSED_RESULT std::string_view subView( sal_Int32 beginIndex ) const
    {
        assert(beginIndex >= 0);
        assert(beginIndex <= getLength());
        return subView(beginIndex, getLength() - beginIndex);
    }

    /**
      Returns a std::string_view that is a view of a substring of this string.

      The substring begins at the specified beginIndex and contains count
      characters.  If either beginIndex or count are negative,
      or beginIndex + count are greater than the length of this string
      then behaviour is undefined.

      @param     beginIndex   the beginning index, inclusive.
      @param     count        the number of characters.
      @return    the specified substring.
    */
    SAL_WARN_UNUSED_RESULT std::string_view subView( sal_Int32 beginIndex, sal_Int32 count ) const
    {
        assert(beginIndex >= 0);
        assert(count >= 0);
        assert(beginIndex <= getLength());
        assert(count <= getLength() - beginIndex);
        return std::string_view(*this).substr(beginIndex, count);
    }
#endif

#ifndef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
    /**
      Concatenates the specified string to the end of this string.

      @param    str   the string that is concatenated to the end
                      of this string.
      @return   a string that represents the concatenation of this string
                followed by the string argument.
    */
    SAL_WARN_UNUSED_RESULT OString concat( const OString & str ) const
    {
        rtl_String* pNew = NULL;
        rtl_string_newConcat( &pNew, pData, str.pData );
        return OString( pNew, SAL_NO_ACQUIRE );
    }
#endif

#ifndef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"
    friend OString operator+( const OString & str1, const OString & str2  )
    {
        return str1.concat( str2 );
    }
#endif

// hide this from internal code to avoid ambiguous lookup error
#ifndef LIBO_INTERNAL_ONLY
    /**
      Returns a new string resulting from replacing n = count characters
      from position index in this string with newStr.

      @param  index   the replacing index in str.
                      The index must be greater or equal as 0 and
                      less or equal as the length of the string.
      @param  count   the count of characters that will replaced
                      The count must be greater or equal as 0 and
                      less or equal as the length of the string minus index.
      @param  newStr  the new substring.
      @return the new string.
    */
    SAL_WARN_UNUSED_RESULT OString replaceAt( sal_Int32 index, sal_Int32 count, const OString& newStr ) const
    {
        rtl_String* pNew = NULL;
        rtl_string_newReplaceStrAt( &pNew, pData, index, count, newStr.pData );
        return OString( pNew, SAL_NO_ACQUIRE );
    }
#endif

#ifdef LIBO_INTERNAL_ONLY
    SAL_WARN_UNUSED_RESULT OString replaceAt( sal_Int32 index, sal_Int32 count, std::string_view newStr ) const
    {
        rtl_String* pNew = NULL;
        rtl_string_newReplaceStrAt_WithLength ( &pNew, pData, index, count, newStr.data(), newStr.size() );
        return OString( pNew, SAL_NO_ACQUIRE );
    }
#endif

    /**
      Returns a new string resulting from replacing all occurrences of
      oldChar in this string with newChar.

      If the character oldChar does not occur in the character sequence
      represented by this object, then the string is assigned with
      str.

      @param    oldChar     the old character.
      @param    newChar     the new character.
      @return   a string derived from this string by replacing every
                occurrence of oldChar with newChar.
    */
    SAL_WARN_UNUSED_RESULT OString replace( char oldChar, char newChar ) const
    {
        rtl_String* pNew = NULL;
        rtl_string_newReplace( &pNew, pData, oldChar, newChar );
        return OString( pNew, SAL_NO_ACQUIRE );
    }

    /**
      Returns a new string resulting from replacing the first occurrence of a
      given substring with another substring.

      @param from  the substring to be replaced

      @param to  the replacing substring

      @param[in,out] index  pointer to a start index; if the pointer is
      non-null: upon entry to the function, its value is the index into the this
      string at which to start searching for the \p from substring, the value
      must be non-negative and not greater than this string's length; upon exit
      from the function its value is the index into this string at which the
      replacement took place or -1 if no replacement took place; if the pointer
      is null, searching always starts at index 0

      @since LibreOffice 3.6
    */
    SAL_WARN_UNUSED_RESULT OString replaceFirst(
        OString const & from, OString const & to, sal_Int32 * index = NULL) const
    {
        rtl_String * s = NULL;
        sal_Int32 i = 0;
        rtl_string_newReplaceFirst(
            &s, pData, from.pData->buffer, from.pData->length,
            to.pData->buffer, to.pData->length, index == NULL ? &i : index);
        return OString(s, SAL_NO_ACQUIRE);
    }

    /**
      Returns a new string resulting from replacing all occurrences of a given
      substring with another substring.

      Replacing subsequent occurrences picks up only after a given replacement.
      That is, replacing from "xa" to "xx" in "xaa" results in "xxa", not "xxx".

      @param from  the substring to be replaced

      @param to  the replacing substring

      @since LibreOffice 3.6
    */
    SAL_WARN_UNUSED_RESULT OString replaceAll(OString const & from, OString const & to) const {
        rtl_String * s = NULL;
        rtl_string_newReplaceAll(
            &s, pData, from.pData->buffer, from.pData->length,
            to.pData->buffer, to.pData->length);
        return OString(s, SAL_NO_ACQUIRE);
    }

    /**
      Converts from this string all ASCII uppercase characters (65-90)
      to ASCII lowercase characters (97-122).

      This function can't be used for language specific conversion.
      If the string doesn't contain characters which must be converted,
      then the new string is assigned with str.

      @return   the string, converted to ASCII lowercase.
    */
    SAL_WARN_UNUSED_RESULT OString toAsciiLowerCase() const
    {
        rtl_String* pNew = NULL;
        rtl_string_newToAsciiLowerCase( &pNew, pData );
        return OString( pNew, SAL_NO_ACQUIRE );
    }

    /**
      Converts from this string all ASCII lowercase characters (97-122)
      to ASCII uppercase characters (65-90).

      This function can't be used for language specific conversion.
      If the string doesn't contain characters which must be converted,
      then the new string is assigned with str.

      @return   the string, converted to ASCII uppercase.
    */
    SAL_WARN_UNUSED_RESULT OString toAsciiUpperCase() const
    {
        rtl_String* pNew = NULL;
        rtl_string_newToAsciiUpperCase( &pNew, pData );
        return OString( pNew, SAL_NO_ACQUIRE );
    }

    /**
      Returns a new string resulting from removing white space from both ends
      of the string.

      All characters that have codes less than or equal to
      32 (the space character) are considered to be white space.
      If the string doesn't contain white spaces at both ends,
      then the new string is assigned with str.

      @return   the string, with white space removed from the front and end.
    */
    SAL_WARN_UNUSED_RESULT OString trim() const
    {
        rtl_String* pNew = NULL;
        rtl_string_newTrim( &pNew, pData );
        return OString( pNew, SAL_NO_ACQUIRE );
    }

    /**
      Returns a token in the string.

      Example:
        sal_Int32 nIndex = 0;
        do
        {
            ...
            OString aToken = aStr.getToken( 0, ';', nIndex );
            ...
        }
        while ( nIndex >= 0 );

      @param    token       the number of the token to return.
      @param    cTok        the character which separate the tokens.
      @param    index       the position at which the token is searched in the
                            string.
                            The index must not be greater than the length of the
                            string.
                            This param is set to the position of the
                            next token or to -1, if it is the last token.
      @return   the token; if either token or index is negative, an empty token
                is returned (and index is set to -1)
    */
    OString getToken( sal_Int32 token, char cTok, sal_Int32& index ) const
    {
        rtl_String * pNew = NULL;
        index = rtl_string_getToken( &pNew, pData, token, cTok, index );
        return OString( pNew, SAL_NO_ACQUIRE );
    }

    /**
      Returns a token from the string.

      The same as getToken(sal_Int32, char, sal_Int32 &), but always passing
      in 0 as the start index in the third argument.

      @param count  the number of the token to return, starting with 0
      @param separator  the character which separates the tokens

      @return  the given token, or an empty string

      @since LibreOffice 3.6
     */
    OString getToken(sal_Int32 count, char separator) const {
        sal_Int32 n = 0;
        return getToken(count, separator, n);
    }

    /**
      Returns the Boolean value from this string.

      This function can't be used for language specific conversion.

      @return   true, if the string is 1 or "True" in any ASCII case.
                false in any other case.
    */
    bool toBoolean() const
    {
        return rtl_str_toBoolean( pData->buffer );
    }

    /**
      Returns the first character from this string.

      @return   the first character from this string or 0, if this string
                is empty.
    */
    char toChar() const
    {
        return pData->buffer[0];
    }

    /**
      Returns the int32 value from this string.

      This function can't be used for language specific conversion.

      @param    radix       the radix (between 2 and 36)
      @return   the int32 represented from this string.
                0 if this string represents no number or one of too large
                magnitude.
    */
    sal_Int32 toInt32( sal_Int16 radix = 10 ) const
    {
        return rtl_str_toInt32( pData->buffer, radix );
    }

    /**
      Returns the uint32 value from this string.

      This function can't be used for language specific conversion.

      @param    radix       the radix (between 2 and 36)
      @return   the uint32 represented from this string.
                0 if this string represents no number or one of too large
                magnitude.

      @since LibreOffice 4.2
    */
    sal_uInt32 toUInt32( sal_Int16 radix = 10 ) const
    {
        return rtl_str_toUInt32( pData->buffer, radix );
    }

    /**
      Returns the int64 value from this string.

      This function can't be used for language specific conversion.

      @param    radix       the radix (between 2 and 36)
      @return   the int64 represented from this string.
                0 if this string represents no number or one of too large
                magnitude.
    */
    sal_Int64 toInt64( sal_Int16 radix = 10 ) const
    {
        return rtl_str_toInt64( pData->buffer, radix );
    }

    /**
      Returns the uint64 value from this string.

      This function can't be used for language specific conversion.

      @param    radix       the radix (between 2 and 36)
      @return   the uint64 represented from this string.
                0 if this string represents no number or one of too large
                magnitude.

      @since LibreOffice 4.1
    */
    sal_uInt64 toUInt64( sal_Int16 radix = 10 ) const
    {
        return rtl_str_toUInt64( pData->buffer, radix );
    }

    /**
      Returns the float value from this string.

      This function can't be used for language specific conversion.

      @return   the float represented from this string.
                0.0 if this string represents no number.
    */
    float toFloat() const
    {
        return rtl_str_toFloat( pData->buffer );
    }

    /**
      Returns the double value from this string.

      This function can't be used for language specific conversion.

      @return   the double represented from this string.
                0.0 if this string represents no number.
    */
    double toDouble() const
    {
        return rtl_str_toDouble( pData->buffer );
    }

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"

    static OStringNumber< int > number( int i, sal_Int16 radix = 10 )
    {
        return OStringNumber< int >( i, radix );
    }
    static OStringNumber< long long > number( long long ll, sal_Int16 radix = 10 )
    {
        return OStringNumber< long long >( ll, radix );
    }
    static OStringNumber< unsigned long long > number( unsigned long long ll, sal_Int16 radix = 10 )
    {
        return OStringNumber< unsigned long long >( ll, radix );
    }
    static OStringNumber< unsigned long long > number( unsigned int i, sal_Int16 radix = 10 )
    {
        return number( static_cast< unsigned long long >( i ), radix );
    }
    static OStringNumber< long long > number( long i, sal_Int16 radix = 10)
    {
        return number( static_cast< long long >( i ), radix );
    }
    static OStringNumber< unsigned long long > number( unsigned long i, sal_Int16 radix = 10 )
    {
        return number( static_cast< unsigned long long >( i ), radix );
    }
    static OStringNumber< float > number( float f )
    {
        return OStringNumber< float >( f );
    }
    static OStringNumber< double > number( double d )
    {
        return OStringNumber< double >( d );
    }
#else
    /**
      Returns the string representation of the integer argument.

      This function can't be used for language specific conversion.

      @param    i           an integer value
      @param    radix       the radix (between 2 and 36)
      @return   a string with the string representation of the argument.
      @since LibreOffice 4.1
    */
    static OString number( int i, sal_Int16 radix = 10 )
    {
        char aBuf[RTL_STR_MAX_VALUEOFINT32];
        return OString(aBuf, rtl_str_valueOfInt32(aBuf, i, radix));
    }
    /// @overload
    /// @since LibreOffice 4.1
    static OString number( unsigned int i, sal_Int16 radix = 10 )
    {
        return number( static_cast< unsigned long long >( i ), radix );
    }
    /// @overload
    /// @since LibreOffice 4.1
    static OString number( long i, sal_Int16 radix = 10 )
    {
        return number( static_cast< long long >( i ), radix );
    }
    /// @overload
    /// @since LibreOffice 4.1
    static OString number( unsigned long i, sal_Int16 radix = 10 )
    {
        return number( static_cast< unsigned long long >( i ), radix );
    }
    /// @overload
    /// @since LibreOffice 4.1
    static OString number( long long ll, sal_Int16 radix = 10 )
    {
        char aBuf[RTL_STR_MAX_VALUEOFINT64];
        return OString(aBuf, rtl_str_valueOfInt64(aBuf, ll, radix));
    }
    /// @overload
    /// @since LibreOffice 4.1
    static OString number( unsigned long long ll, sal_Int16 radix = 10 )
    {
        char aBuf[RTL_STR_MAX_VALUEOFUINT64];
        return OString(aBuf, rtl_str_valueOfUInt64(aBuf, ll, radix));
    }

    /**
      Returns the string representation of the float argument.

      This function can't be used for language specific conversion.

      @param    f           a float.
      @return   a string with the decimal representation of the argument.
      @since LibreOffice 4.1
    */
    static OString number( float f )
    {
        char aBuf[RTL_STR_MAX_VALUEOFFLOAT];
        return OString(aBuf, rtl_str_valueOfFloat(aBuf, f));
    }

    /**
      Returns the string representation of the double argument.

      This function can't be used for language specific conversion.

      @param    d           a double.
      @return   a string with the decimal representation of the argument.
      @since LibreOffice 4.1
    */
    static OString number( double d )
    {
        char aBuf[RTL_STR_MAX_VALUEOFDOUBLE];
        return OString(aBuf, rtl_str_valueOfDouble(aBuf, d));
    }
#endif

    /**
      Returns the string representation of the sal_Bool argument.

      If the sal_Bool is true, the string "true" is returned.
      If the sal_Bool is false, the string "false" is returned.
      This function can't be used for language specific conversion.

      @param    b   a sal_Bool.
      @return   a string with the string representation of the argument.
      @deprecated use boolean()
    */
    SAL_DEPRECATED("use boolean()") static OString valueOf( sal_Bool b )
    {
        return boolean(b);
    }

    /**
      Returns the string representation of the boolean argument.

      If the argument is true, the string "true" is returned.
      If the argument is false, the string "false" is returned.
      This function can't be used for language specific conversion.

      @param    b   a bool.
      @return   a string with the string representation of the argument.
      @since LibreOffice 4.1
    */
    static OString boolean( bool b )
    {
        char aBuf[RTL_STR_MAX_VALUEOFBOOLEAN];
        return OString(aBuf, rtl_str_valueOfBoolean(aBuf, b));
    }

    /**
      Returns the string representation of the char argument.

      @param    c   a character.
      @return   a string with the string representation of the argument.
      @deprecated use operator, function or constructor taking char or sal_Unicode argument
    */
    SAL_DEPRECATED("convert to OString or use directly") static OString valueOf( char c )
    {
        return OString( &c, 1 );
    }

    /**
      Returns the string representation of the int argument.

      This function can't be used for language specific conversion.

      @param    i           a int32.
      @param    radix       the radix (between 2 and 36)
      @return   a string with the string representation of the argument.
      @deprecated use number()
    */
    SAL_DEPRECATED("use number()") static OString valueOf( sal_Int32 i, sal_Int16 radix = 10 )
    {
        return number( i, radix );
    }

    /**
      Returns the string representation of the long argument.

      This function can't be used for language specific conversion.

      @param    ll          a int64.
      @param    radix       the radix (between 2 and 36)
      @return   a string with the string representation of the argument.
      @deprecated use number()
    */
    SAL_DEPRECATED("use number()") static OString valueOf( sal_Int64 ll, sal_Int16 radix = 10 )
    {
        return number( ll, radix );
    }

    /**
      Returns the string representation of the float argument.

      This function can't be used for language specific conversion.

      @param    f           a float.
      @return   a string with the string representation of the argument.
      @deprecated use number()
    */
    SAL_DEPRECATED("use number()") static OString valueOf( float f )
    {
        return number(f);
    }

    /**
      Returns the string representation of the double argument.

      This function can't be used for language specific conversion.

      @param    d           a double.
      @return   a string with the string representation of the argument.
      @deprecated use number()
    */
    SAL_DEPRECATED("use number()") static OString valueOf( double d )
    {
        return number(d);
    }

#if defined LIBO_INTERNAL_ONLY
    operator std::string_view() const { return {getStr(), sal_uInt32(getLength())}; }
#endif

#if defined LIBO_INTERNAL_ONLY
    // A wrapper for the first expression in an
    //
    //   OString::Concat(e1) + e2 + ...
    //
    // concatenation chain, when neither of the first two e1, e2 is one of our rtl string-related
    // classes (so something like
    //
    //   OString s = "a" + (b ? std::string_view("c") : std::string_view("dd"));
    //
    // would not compile):
    template<typename T> [[nodiscard]] static
    typename std::enable_if_t<
        ToStringHelper<T>::allowOStringConcat, OStringConcat<OStringConcatMarker, T>>
    Concat(T const & value) { return OStringConcat<OStringConcatMarker, T>({}, value); }

    // This overload is needed so that an argument of type 'char const[N]' ends up as
    // 'OStringConcat<rtl::OStringConcatMarker, char const[N]>' rather than as
    // 'OStringConcat<rtl::OStringConcatMarker, char[N]>':
    template<typename T, std::size_t N> [[nodiscard]] static
    typename std::enable_if_t<
        ToStringHelper<T[N]>::allowOStringConcat, OStringConcat<OStringConcatMarker, T[N]>>
    Concat(T (& value)[N]) { return OStringConcat<OStringConcatMarker, T[N]>({}, value); }
#endif
};

#if defined LIBO_INTERNAL_ONLY
inline bool operator ==(OString const & lhs, OStringConcatenation const & rhs)
{ return lhs == std::string_view(rhs); }
inline bool operator !=(OString const & lhs, OStringConcatenation const & rhs)
{ return lhs != std::string_view(rhs); }
inline bool operator ==(OStringConcatenation const & lhs, OString const & rhs)
{ return std::string_view(lhs) == rhs; }
inline bool operator !=(OStringConcatenation const & lhs, OString const & rhs)
{ return std::string_view(lhs) != rhs; }
#endif

/* ======================================================================= */

#ifdef LIBO_INTERNAL_ONLY // "RTL_FAST_STRING"

/**
 @internal
*/
template<>
struct ToStringHelper< OString >
    {
    static std::size_t length( const OString& s ) { return s.getLength(); }
    static char* addData( char* buffer, const OString& s ) { return addDataHelper( buffer, s.getStr(), s.getLength()); }
    static const bool allowOStringConcat = true;
    static const bool allowOUStringConcat = false;
    };

/**
 @internal
*/
template<std::size_t N>
struct ToStringHelper< OStringLiteral<N> >
    {
    static constexpr std::size_t length( const OStringLiteral<N>& str ) { return str.getLength(); }
    static char* addData( char* buffer, const OStringLiteral<N>& str ) { return addDataHelper( buffer, str.getStr(), str.getLength() ); }
    static const bool allowOStringConcat = true;
    static const bool allowOUStringConcat = false;
    };

/**
 @internal
*/
template< typename charT, typename traits, typename T1, typename T2 >
inline std::basic_ostream<charT, traits> & operator <<(
    std::basic_ostream<charT, traits> & stream, OStringConcat< T1, T2 >&& concat)
{
    return stream << OString( std::move(concat) );
}
#endif


/** A helper to use OStrings with hash maps.

    Instances of this class are unary function objects that can be used as
    hash function arguments to std::unordered_map and similar constructs.
 */
struct OStringHash
{
    /** Compute a hash code for a string.

        @param rString
        a string.

        @return
        a hash code for the string.  This hash code should not be stored
        persistently, as its computation may change in later revisions.
     */
    size_t operator()( const OString& rString ) const
        { return static_cast<size_t>(rString.hashCode()); }
};

/** Equality functor for classic c-strings (i.e., null-terminated char* strings). */
struct CStringEqual
{
    bool operator()( const char* p1, const char* p2) const
        { return rtl_str_compare(p1, p2) == 0; }
};

/** Hashing functor for classic c-strings (i.e., null-terminated char* strings). */
struct CStringHash
{
    size_t operator()(const char* p) const
        { return rtl_str_hashCode(p); }
};

/* ======================================================================= */

/**
    Support for rtl::OString in std::ostream (and thus in
    CPPUNIT_ASSERT or SAL_INFO macros, for example).

    @since LibreOffice 4.0
 */
template< typename charT, typename traits > std::basic_ostream<charT, traits> &
operator <<(
    std::basic_ostream<charT, traits> & stream, OString const & rString)
{
    return stream << rString.getStr();
        // best effort; potentially loses data due to embedded null characters
}

} /* Namespace */

#ifdef RTL_STRING_UNITTEST
namespace rtl
{
typedef rtlunittest::OString OString;
}
#undef RTL_STRING_CONST_FUNCTION
#endif

#if defined LIBO_INTERNAL_ONLY && !defined RTL_STRING_UNITTEST
using ::rtl::OString;
using ::rtl::OStringChar;
using ::rtl::OStringConcatenation;
using ::rtl::OStringHash;
using ::rtl::OStringLiteral;
#endif

/// @cond INTERNAL
/**
  Make OString hashable by default for use in STL containers.

  @since LibreOffice 6.0
*/
#if defined LIBO_INTERNAL_ONLY
namespace std {

template<>
struct hash<::rtl::OString>
{
    std::size_t operator()(::rtl::OString const & s) const
    { return std::size_t(s.hashCode()); }
};

}

#endif
/// @endcond

#endif // INCLUDED_RTL_STRING_HXX

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */