default constructed
时间: 2023-10-07 22:14:37 浏览: 52
"Default constructed" refers to an object that has been created using its default constructor, which is a constructor that takes no arguments. When an object is default constructed, its member variables are initialized to their default values according to their types. For example, for numeric types such as int or double, the default value is 0, and for bool, the default value is false. It is also possible for user-defined types to have a default constructor defined by the user, in which case the object is initialized according to the implementation of that constructor.
相关问题
Low-density parity-check codes constructed from protographs
can achieve near-Shannon limit performance. Can you explain how protograph-based LDPC codes work and what makes them effective in achieving high accuracy?
Sure, I'd be happy to explain. LDPC codes are a type of error-correcting code used in digital communication systems to mitigate the effects of noise and interference. Protograph-based LDPC codes are a type of LDPC code that use a protograph matrix to describe the code structure. The protograph matrix specifies the connectivity pattern of the code's check matrix, which is used to detect and correct errors in the transmitted data.
The use of protographs allows for the creation of highly structured LDPC codes with a well-defined pattern of connections between nodes. This structure makes it easier to design and analyze the codes, which leads to better performance. Additionally, protograph-based LDPC codes can be optimized for specific transmission scenarios, further improving their performance.
The near-Shannon limit performance of protograph-based LDPC codes can be attributed to their ability to correct a high percentage of errors with a low probability of error. This is achieved through the iterative decoding process, where the received data is repeatedly processed through the protograph-based LDPC code until the probability of error is minimized. By carefully constructing the protograph matrix and optimizing the decoding algorithm, protograph-based LDPC codes can achieve extremely high accuracy in noisy communication channels.
ob_link_constructed和ob_link_init谁先被调用
在 GObject 中,对象的初始化过程分为两个阶段:`constructed` 和 `init`。其中 `constructed` 阶段是在对象层次结构被建立后调用的,而 `init` 阶段则是在对象实例化完成后调用的。
因此,在使用 GObject 建立对象时,`constructed` 阶段会先被调用,然后是 `init` 阶段。对于 `ob_link` 对象来说,`ob_link_constructed` 会先被调用,然后是 `ob_link_init`。
在 `constructed` 阶段,对象的基类和子类的成员都已经被初始化,我们可以在这个阶段做一些与成员变量有关的初始化工作。而在 `init` 阶段,我们可以对对象进行更加详细的初始化,包括为成员变量赋初值、连接信号等。
需要注意的是,在实现一个自定义 GObject 类时,应当尽量避免手动调用 `constructed` 和 `init` 方法,而是应该使用 GObject 提供的宏来完成初始化工作。这样可以确保在对象初始化过程中不会出现错误。