Question

我想在C / C ++程序中将字符串/ char转换为\ uxxx格式。支持我有一个字符'A'，我想打印转换为\ u0041（标准unicode）。

第二件事是我使用unix命令实用程序来打印（printf）以打印\ uxxx字符串tto char。我尝试使用“\ u092b”它打印的字符与我的字体文件不同。任何人都可以解释这背后的原因。

Answer 1

这是使用标准C ++执行此操作的函数（尽管取决于CharT，它可能有一些要求，某些有效的实现定义的行为不符合）。

#include <codecvt>
#include <sstream>
#include <iomanip>
#include <iostream>

template<typename CharT,typename traits,typename allocator>
std::basic_string<CharT,traits,allocator>
to_uescapes(std::basic_string<CharT,traits,allocator> const &input)
{
    // string converter from CharT to char. If CharT = char then no conversion is done.
    // if CharT is char32_t or char16_t then the conversion is UTF-32/16 -> UTF-8. Not all implementations support this yet.
    // if CharT is something else then this uses implementation defined encodings and will only work for us if the implementation uses UTF-8 as the narrow char encoding
    std::wstring_convert<std::codecvt<CharT,char,std::mbstate_t>,CharT> convertA;

    // string converter from UTF-8 -> UTF-32. Not all implementations support this yet
    std::wstring_convert<std::codecvt<char32_t,char,std::mbstate_t>,char32_t> convertB;

    // convert from input encoding to UTF-32 (Assuming convertA produces UTF-8 string)
    std::u32string u32input = convertB.from_bytes(convertA.to_bytes(input));

    std::basic_stringstream<CharT,traits,allocator> ss;
    ss.fill('0');
    ss << std::hex;
    for(char32_t c : u32input) {
        if(c < U'\U00010000')
            ss << convertA.from_bytes("\\u") << std::setw(4) << (unsigned int)c;
        else
            ss << convertA.from_bytes("\\U") << std::setw(8) << (unsigned int)c;
    }
    return ss.str();
}

template<typename CharT>
std::basic_string<CharT>
to_uescapes(CharT const *input)
{
    return to_uescapes(std::basic_string<CharT>(input));
}

int main() {
    std::string s = to_uescapes(u8"Hello \U00010000");
    std::cout << s << '\n';
}

这应该打印：

\ u0048 \ u0065 \ u006c \ u006c \ u006f \ u0020 \ U00010000

在C / C ++中将字符转换为\ use格式

1 个答案: