123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124 | // Copyright (C) 2016 Intel Corporation.// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only#ifndef QSTRINGALGORITHMS_P_H#define QSTRINGALGORITHMS_P_H//// W A R N I N G// -------------//// This file is not part of the Qt API. It exists for the convenience// of internal files. This header file may change from version to version// without notice, or even be removed.//// We mean it.//#include"qstring.h"#include"qlocale_p.h"// for ascii_isspace QT_BEGIN_NAMESPACE template<typename StringType>struct QStringAlgorithms {typedef typename StringType::value_type Char;typedef typename StringType::size_type size_type;typedef typename std::remove_cv<StringType>::type NakedStringType;static const bool isConst =std::is_const<StringType>::value;staticinlineboolisSpace(char ch) {returnascii_isspace(ch); }staticinlineboolisSpace(QChar ch) {return ch.isSpace(); }// Surrogate pairs are not handled in either of the functions below. That is// not a problem because there are no space characters (Zs, Zl, Zp) outside the// Basic Multilingual Plane.staticinline StringType trimmed_helper_inplace(NakedStringType &str,const Char *begin,const Char *end){// in-place trimming: Char *data =const_cast<Char *>(str.cbegin());if(begin != data)memmove(data, begin, (end - begin) *sizeof(Char)); str.resize(end - begin);returnstd::move(str);}staticinline StringType trimmed_helper_inplace(const NakedStringType &,const Char *,const Char *){// can't happenQ_UNREACHABLE_RETURN(StringType());}struct TrimPositions {const Char *begin;const Char *end;};// Returns {begin, end} where:// - "begin" refers to the first non-space character// - if there is a sequence of one or more space chacaters at the end,// "end" refers to the first character in that sequence, otherwise// "end" is str.cend()[[nodiscard]]static TrimPositions trimmed_helper_positions(const StringType &str){const Char *begin = str.cbegin();const Char *end = str.cend();// skip white space from endwhile(begin < end &&isSpace(end[-1]))--end;// skip white space from startwhile(begin < end &&isSpace(*begin)) begin++;return{begin, end};}staticinline StringType trimmed_helper(StringType &str){constauto[begin, end] =trimmed_helper_positions(str);if(begin == str.cbegin() && end == str.cend())return str;if(!isConst && str.isDetached())returntrimmed_helper_inplace(str, begin, end);returnStringType(begin, end - begin);}staticinline StringType simplified_helper(StringType &str){if(str.isEmpty())return str;const Char *src = str.cbegin();const Char *end = str.cend(); NakedStringType result = isConst || !str.isDetached() ?StringType(str.size(),Qt::Uninitialized) :std::move(str); Char *dst =const_cast<Char *>(result.cbegin()); Char *ptr = dst;bool unmodified =true;while(true) {while(src != end &&isSpace(*src))++src;while(src != end && !isSpace(*src))*ptr++ = *src++;if(src == end)break;if(*src !=QChar::Space) unmodified =false;*ptr++ =QChar::Space;}if(ptr != dst && ptr[-1] ==QChar::Space)--ptr; qsizetype newlen = ptr - dst;if(isConst && newlen == str.size() && unmodified) {// nothing happened, return the originalreturn str;} result.resize(newlen);return result;}}; QT_END_NAMESPACE #endif// QSTRINGALGORITHMS_P_H
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