Memcpy unique_ptr到向量

Question

int ReadByName (std::vector<unsigned char> &value, const char handleName[], std::ostream &out, const long &port, const AmsAddr &server)
{
        uint32_t bytesRead;

        out << __FUNCTION__ << "():  ";
        
        if (this->handle == 0)
            handle = getHandleByName(out, port, server, handleName);
        if (bufferSize == 0)
            bufferSize = getSymbolSize(out, port, server, handleName);

        const auto buffer = std::unique_ptr<uint8_t>(new uint8_t[bufferSize]);

        const long status = AdsSyncReadReqEx2(  port,
                                                &server,
                                                ADSIGRP_SYM_VALBYHND,
                                                handle,
                                                bufferSize,
                                                buffer.get(),
                                                &bytesRead);
        
        if (status) {
            out << "ADS read failed with: " << std::dec << status << '\n';
            return 2;
        }
        value.clear();
        value.reserve(bufferSize);
        std::memcpy(&value, buffer.get(), bufferSize);
        return 0;
}

Answer 1

解决这个问题的正确方法是什么？

它将直接读入向量，而不是稍后复制的单独数组。

如果AdsSyncReadReqEx2()的读取操作失败，则值已经被清除。