C ++从字符串制作Unicode char
c++ making a unicode char from a string
>我有这样的字符串
string s = "0081";
我需要像这样制作一个字符串
string c = "u0081"
如何从长度为 1 的原始字符串制作长度为 4 的字符串?
编辑:我的错误,"\u0081"不是字符(1 字节)而是 2 字节字符/字符串?所以我作为输入的是一个二进制,1000 0001,这是0x81,这就是我的字符串"0081"的来源。从这个0x81转到字符串 c = "\u0081" 无论该值是什么,会更容易吗?感谢所有的帮助
这是整个过程,基于我在其他地方的评论中链接到的一些代码。
string s = "0081";
long codepoint = strtol(s.c_str(), NULL, 16);
string c = CodepointToUTF8(codepoint);
std::string CodepointToUTF8(long codepoint)
{
std::string out;
if (codepoint <= 0x7f)
out.append(1, static_cast<char>(codepoint));
else if (codepoint <= 0x7ff)
{
out.append(1, static_cast<char>(0xc0 | ((codepoint >> 6) & 0x1f)));
out.append(1, static_cast<char>(0x80 | (codepoint & 0x3f)));
}
else if (codepoint <= 0xffff)
{
out.append(1, static_cast<char>(0xe0 | ((codepoint >> 12) & 0x0f)));
out.append(1, static_cast<char>(0x80 | ((codepoint >> 6) & 0x3f)));
out.append(1, static_cast<char>(0x80 | (codepoint & 0x3f)));
}
else
{
out.append(1, static_cast<char>(0xf0 | ((codepoint >> 18) & 0x07)));
out.append(1, static_cast<char>(0x80 | ((codepoint >> 12) & 0x3f)));
out.append(1, static_cast<char>(0x80 | ((codepoint >> 6) & 0x3f)));
out.append(1, static_cast<char>(0x80 | (codepoint & 0x3f)));
}
return out;
}
请注意,此代码不执行任何错误检查,因此,如果向其传递无效的代码点,则会返回无效字符串。
你来了:
unsigned int x;
std::stringstream ss;
ss << std::hex << "1081";
ss >> x;
wchar_t wc1 = x;
wchar_t wc2 = L'u1081';
assert(wc1 == wc2);
std::wstring ws(1, wc);