尝试获取不存在的节点时如何不出现任何错误
How to not have any error when try to get a not existing node
有人可以知道 "try" 中的以下代码有什么样的异常 return 吗？
我尝试使用 3 种 "catch (exception)"，但似乎没有一个有效。
try
{
std::cout << "try to get not existing path" << std::endl;
std::string path = this->m_Tree.get<std::string>(PATH);
}
catch (const boost::property_tree::ptree_bad_path& e)
{
std::cout << "ptree_bad_path" << std::endl;
}
感谢您的帮助。
查看文档：
Three Ways of Getting Data
There are three versions of get: get, get (default-value version), and get_optional, which differ by failure handling strategy. All versions take path specifier, which determines in which key to search for a value. It can be a single key, or a path to key, where path elements are separated with a special character (a '.' if not specified differently). For example debug.logging.errorlevel might be a valid path with dot as a separator.
所以，只要使用 get_optional<std::string> 我会说
ptree pt;
/* ... */
boost::optional<float> v = pt.get_optional<float>("a.path.to.float.value");
有人可以知道 "try" 中的以下代码有什么样的异常 return 吗？ 我尝试使用 3 种 "catch (exception)"，但似乎没有一个有效。
try
{
std::cout << "try to get not existing path" << std::endl;
std::string path = this->m_Tree.get<std::string>(PATH);
}
catch (const boost::property_tree::ptree_bad_path& e)
{
std::cout << "ptree_bad_path" << std::endl;
}
感谢您的帮助。
查看文档：
Three Ways of Getting Data
There are three versions of get: get, get (default-value version), and get_optional, which differ by failure handling strategy. All versions take path specifier, which determines in which key to search for a value. It can be a single key, or a path to key, where path elements are separated with a special character (a '.' if not specified differently). For example debug.logging.errorlevel might be a valid path with dot as a separator.
所以，只要使用 get_optional<std::string> 我会说
ptree pt;
/* ... */
boost::optional<float> v = pt.get_optional<float>("a.path.to.float.value");