简单的算法代码：
#include <iostream>
#include <string>
std::string::size_type GetLengthWithUTF(std::string &sValue);
int main()
{
std::string sTestValueUTF8 = "\xD0\xB6\xD0\xB6\xD0\xB6";
std::string sTestValueASCII = "\x67\x67\x67";
std::string sTestValueMIX = "\x67\x67\x67\xD0\xB6\xD0\xB6\xD0\xB6";
std::string::size_type iFuncResult = 0;
std::cout << "=========== START TEST ==========\n\n";
std::cout << "+TEST UTF8 STRING\n";
std::cout << "+----+Bytes of string (sTestValueUTF8.length()) = " << sTestValueUTF8.length() << "\n";
iFuncResult = GetLengthWithUTF(sTestValueUTF8);
std::cout << "+----+Function result (GetLengthWithUTF(\"" << sTestValueUTF8 << "\")) = " << iFuncResult<< "\n\n";
std::cout << "+TEST ASCII STRING\n";
std::cout << "+----+Bytes of string (sTestValueASCII.length()) = " << sTestValueASCII.length() << "\n";
iFuncResult = GetLengthWithUTF(sTestValueASCII);
std::cout << "+----+Function result (GetLengthWithUTF(\"" << sTestValueASCII << "\")) = " << iFuncResult<< "\n\n";
std::cout << "+TEST MIX STRING\n";
std::cout << "+----+Bytes of string (sTestValueMIX.length()) = " << sTestValueMIX.length() << "\n";
iFuncResult = GetLengthWithUTF(sTestValueMIX);
std::cout << "+----+Function result (GetLengthWithUTF(\"" << sTestValueMIX << "\")) = " << iFuncResult<< "\n\n";
std::cout << "\n=========== END TEST ==========\n\n";
}
std::string::size_type GetLengthWithUTF(std::string &sValue)
{
std::cout << " +----+START GetLengthWithUTF\n";
std::cout << " +Input string is: " << sValue << "\n";
std::string::size_type i;
std::cout << " +Start cycle\n";
int iCountUTF8characters = 0;
for (i = 0; i < sValue.length(); i++)
{
std::cout << " +----+Iteration N " << i << "\n";
std::cout << " +Current character is: " << sValue[i] << ", integer value = " << (int)sValue[i] << "\n";
if (sValue[i] > 127)
{
iCountUTF8characters++;
std::cout << " +----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: " << iCountUTF8characters << "\n";
}
else
{
std::cout << " +----+If statement (sValue[i] > 127) is false.\n";
}
}
std::cout << " +End cycle\n";
iCountUTF8characters = iCountUTF8characters / 2;
std::cout << " +Return sValue.length() - (iCountUTF8characters / 2) ---> " << sValue.length() << " - (" << iCountUTF8characters << " / 2) = " << (sValue.length() - (std::string::size_type)iCountUTF8characters) <<"\n";
std::cout << " +----+ASCIID GetLengthWithUTF\n";
return (sValue.length() - (std::string::size_type)iCountUTF8characters);
}
控制台编译命令：
AIX 6
g++ -o test test.cpp
RHEL Server 6.7 Santiago
g++ -o test test.cpp
Microsoft Windows v10.0.14393
cl /EHsc test.cpp
=========== START TEST ==========
+TEST UTF8 STRING
+----+Bytes of string (sTestValueUTF8.length()) = 6
+----+START GetLengthWithUTF
+Input string is: жжж
+Start cycle
+----+Iteration N 0
+Current character is: Ь integer value = 208
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 1
+----+Iteration N 1
+Current character is: ֬ integer value = 182
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 2
+----+Iteration N 2
+Current character is: Ь integer value = 208
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 3
+----+Iteration N 3
+Current character is: ֬ integer value = 182
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 4
+----+Iteration N 4
+Current character is: Ь integer value = 208
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 5
+----+Iteration N 5
+Current character is: ֬ integer value = 182
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 6
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 6 - (3 / 2) = 3
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("жжж")) = 3
+TEST ASCII STRING
+----+Bytes of string (sTestValueASCII.length()) = 3
+----+START GetLengthWithUTF
+Input string is: ggg
+Start cycle
+----+Iteration N 0
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 3 - (0 / 2) = 3
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("ggg")) = 3
+TEST MIX STRING
+----+Bytes of string (sTestValueMIX.length()) = 9
+----+START GetLengthWithUTF
+Input string is: gggжжж
+Start cycle
+----+Iteration N 0
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 3
+Current character is: Ь integer value = 208
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 1
+----+Iteration N 4
+Current character is: ֬ integer value = 182
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 2
+----+Iteration N 5
+Current character is: Ь integer value = 208
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 3
+----+Iteration N 6
+Current character is: ֬ integer value = 182
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 4
+----+Iteration N 7
+Current character is: Ь integer value = 208
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 5
+----+Iteration N 8
+Current character is: ֬ integer value = 182
+----+If statement (sValue[i] > 127) is true, value of iCountUTF8characters is: 6
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 9 - (3 / 2) = 6
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("gggжжж")) = 6
=========== END TEST ==========
RHEL Server 6.7 Santiago
=========== START TEST ==========
+TEST UTF8 STRING
+----+Bytes of string (sTestValueUTF8.length()) = 6
+----+START GetLengthWithUTF
+Input string is: жжж
+Start cycle
+----+Iteration N 0
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 3
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 4
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 5
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 6 - (0 / 2) = 6
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("жжж")) = 6
+TEST ASCII STRING
+----+Bytes of string (sTestValueASCII.length()) = 3
+----+START GetLengthWithUTF
+Input string is: ggg
+Start cycle
+----+Iteration N 0
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 3 - (0 / 2) = 3
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("ggg")) = 3
+TEST MIX STRING
+----+Bytes of string (sTestValueMIX.length()) = 9
+----+START GetLengthWithUTF
+Input string is: gggжжж
+Start cycle
+----+Iteration N 0
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 3
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 4
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 5
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 6
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 7
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 8
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 9 - (0 / 2) = 9
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("gggжжж")) = 9
=========== END TEST ==========
Microsoft Windows v10.0.14393
=========== START TEST ==========
+TEST UTF8 STRING
+----+Bytes of string (sTestValueUTF8.length()) = 6
+----+START GetLengthWithUTF
+Input string is: жжж
+Start cycle
+----+Iteration N 0
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 3
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 4
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 5
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 6 - (0 / 2) = 6
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("жжж")) = 6
+TEST ASCII STRING
+----+Bytes of string (sTestValueASCII.length()) = 3
+----+START GetLengthWithUTF
+Input string is: ggg
+Start cycle
+----+Iteration N 0
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 3 - (0 / 2) = 3
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("ggg")) = 3
+TEST MIX STRING
+----+Bytes of string (sTestValueMIX.length()) = 9
+----+START GetLengthWithUTF
+Input string is: gggжжж
+Start cycle
+----+Iteration N 0
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 1
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 2
+Current character is: g, integer value = 103
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 3
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 4
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 5
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 6
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 7
+Current character is: Ь integer value = -48
+----+If statement (sValue[i] > 127) is false.
+----+Iteration N 8
+Current character is: ֬ integer value = -74
+----+If statement (sValue[i] > 127) is false.
+End cycle
+Return sValue.length() - (iCountUTF8characters / 2) ---> 9 - (0 / 2) = 9
+----+ASCIID GetLengthWithUTF
+----+Function result (GetLengthWithUTF("gggжжж")) = 9
=========== END TEST ==========
算法必须计算字符串中的字符数。从测试结果中可以看出，它只能在AIX下正常工作。
如果有人帮助我理解这种算法对于不同操作系统的行为的荒谬，我会很高兴的。该算法是在OS AIX下创建的。从AIX迁移到LINUX之后发现它存在问题，并且我进行了更广泛的测试，您可以看到其结果。我的主要问题是该死的算法在AIX下是如何工作的。我无法以任何合理的方式解释它。
答案 0 :(得分：4)
这两种系统似乎在处理字符符号的方式上有所不同，这是标准所允许的。您的AIX编译器将new { controller = "Home", .. }视为无符号，而其他两个系统将它们视为已签名。
在具有无符号字符的系统上，条件char的行为完全符合预期。但是，相同的表达式在具有签名字符的系统上永远不会成功。
这就是为什么你得到代码为128及以上的字符的负数。例如，sValue[i] > 127在被视为单字节有符号值时变为208。
您可以通过强制转换为无符号，或通过使用位掩码检查8位来解决此问题：
-48