c++ - 如何使用 std:ifstreambuf_iterator 修复错误?

Question

我有这个简单的代码，它必须从文件中迭代四个字节并将其传递给函数 utf8::utf32to8，它将文件从 utf32 编码转换为 utf8：

ifstream my_file(sourceFilePath, std::ifstream::binary);

vector<unsigned char> res_utf8;
utf8::utf32to8(std::istreambuf_iterator<char32_t>(my_file),
               std::istreambuf_iterator<char32_t>(),
               back_inserter(res_utf8));
out.write((char*)&res_utf8[0], res_utf8.size());

但是当我编译我得到这个错误：

error: invalid user-defined conversion from 'std::ifstream {aka std::basic_ifstream<char>}' to 'std::istreambuf_iterator<char32_t>::streambuf_type* {aka std::basic_streambuf<char32_t, std::char_traits<char32_t> >*}' [-fpermissive]
         utf8::utf32to8(std::istreambuf_iterator<char32_t>(my_file),
                                                                  ^

请帮助我成功编译此代码。