Question

使用boost序列化库我有一个非常简单的serialize()成员函数，如：

template <class Archive>
  void serialize( Archive& ar, unsigned version )
  {
     ar & m_Searcher;
  }

...我想保持这么简单（我不想特别使用拆分）。但在写作的情况下，我想在实际写作之前为m_Searcher做一些“准备”。

{
  if( this-is-a-writing-operation )
     do-some-preparation( m_Searcher )

  ar & m_Searcher;
}

有没有简单的方法可以区分读写操作？

Answer 1

我认为你可以不分裂来做到这一点，这是通常的方式：

if (Archive::is_saving::value) 
   doSomething();

这是继承自档案馆使用的基本界面，位于boost/archive/detail/interface_[ia]archive.hpp

以下代码演示了1.42

似乎是一个合理的解决方案

#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <boost/archive/xml_oarchive.hpp>
#include <boost/archive/xml_iarchive.hpp>

// oarchive:
//text
static_assert(!boost::archive::text_oarchive::is_loading::value, "out is loading");
static_assert(boost::archive::text_oarchive::is_saving::value, "out isn't saving");

//xml
static_assert(!boost::archive::xml_oarchive::is_loading::value, "out is loading");
static_assert(boost::archive::xml_oarchive::is_saving::value, "out isn't saving");

// iarchive:
//text
static_assert(boost::archive::text_iarchive::is_loading::value, "out is loading");
static_assert(!boost::archive::text_iarchive::is_saving::value, "out isn't saving");

//xml
static_assert(boost::archive::xml_iarchive::is_loading::value, "out is loading");
static_assert(!boost::archive::xml_iarchive::is_saving::value, "out isn't saving");

我有点谨慎依赖这样的事情 - 如果有人写了一个同时输入和输出和的存档，多重继承可能会破坏它，我不清楚这是多么的永恒并公开这部分界面应该是。

如何区分boost序列化中的读/写操作？

1 个答案: