C++-运行时类型识别




墨衍会员
·
AI 创作全网分发
墨衍智能分发
本文由作者通过墨衍一键同步至各平台
1分发平台
100+累计阅读
184平均单平台
已同步平台
优快云
微信公众号
微博
知乎
掘金
百家号
博客园
抖音
小红书
你的文章也可以这样分发
墨衍会员 ¥399起/年,写一次发全网
我也要 →
码龄17年
C++-运行时类型识别




C++/C/lisp
当前文章被以下社区和专栏收录:
c++11运行时类型识别(RTTI)
//by 鸟哥 演示运行时类型识别 //有疑问请留言或加群 1032082534 #include <iostream> #include <typeinfo> #include <cstring> using namespace std; class Parent { public: virtual ~Parent(){}; }; class Chi...
【C++特殊工具与技术】优化内存分配(六):运行时类型识别
运行时类型识别(Runtime Type Identification, RTTI)是 C++ 标准提供的一组机制,允许程序在运行时获取对象的类型信息。RTTI 主要用于处理多态场景下的类型判断,是面向对象编程中解决类型转换、动态分发等问题的重要工具。
【Ultrascale+ MPSOC学习记录】6、从eMMC启动翻车
因为MPSOC还有一种启动模式是eMMC,接下来咱就实现从eMMC启动。
运行时类型识别
前言我们知道,在类的继承中可以通过基类的指针(或引用)指向派生类的对象,利用多态性执行派生类中提供的功能。但这仅限与调用基类中声明的虚函数。如果希望对于一部分派生类的对象,调用派生类中引入的新函数,则无法通过基类指针进行。我们可以通过static_cast,将基类指针转换成派生类指针。但这样做并不安全,只能在指针所指向的对象类型明确的情况下执行。而有时只有在运行时才能知道指针所指对象的实际类型是声明
国产麒麟系统PXE安装-UEFI引导
注意: 适用uefi引导 适用x86_64架构 一键部署脚本扣我 1.上传ISO到PXE服务器,拷贝ISO文件 # mkdir /kylin_iso # mount -o loop Kylin-Server-10-SP1-Release-Build04-20200711-x86_64.iso /kylin_iso/ 2.配置http,获取安装源 # yum -y install httpd # mkdir /var/www/html/{ks,kylin} # 注意一定是"/kylin_iso/
多个MOS管并联应用场景的四大要点
动态运行时,阈值电压Vgsth最低的MOS管首先打开,最后关闭。这种MOS管一般会占据更多的开关损耗,并且在开关转换过程中,承担了更高的电应力。
C/C++内存与运行时深入研究
武汉理工大学数据结构综合实验——连连看游戏综合实践
文章目录实验目的主要仪器设备及耗材一、实验要求二、分析与设计(非线性结构)1.数据结构的设计2.核心算法设计一条直线消子两条直线消子三条直线消子初始化游戏地图搜寻路径提示和重排3.测试用例设计4.测试效果总结 实验目的 (1)线性结构实验目的 调研连连看游戏,了解连连看游戏的功能和规则等 掌握集成开发工具VS2019的使用和C++的基础编程 了解MFC框架 了解线性结构,掌握数组的遍历、消子和胜负判断等算法 了解企业软件开发过程,应用迭代开发思路进行项目开发,养成良好的编程习惯和培养软件工程化思维 .
c++之运行时类型识别
这一部分将讨论C++中两个支持”现代 面向对象程序设计“的特征。运行时类型识别(Run-Time Type Identification,RTTI)和强制转换运算符。C++的初始定义并没有包含这两个特征,增加他们是为了增强C++对运行时多态的支持。RTTI允许应用程序在执行期间标识一个对象的类型。而强制转换运算符可以给你带来更安全的、更加可控的类型转换方法。你将会看到强制转换运算符之一dynami
LVGL多线程编程避坑指南:从音乐播放器项目看UI与后台任务如何安全协作
本文深入探讨LVGL在多线程环境下的安全协作问题,以音乐播放器项目为例,解析UI与后台任务(如mplayer音频播放器)的典型冲突场景。提供全局互斥锁规范、任务队列异步处理等核心策略,并分享mplayer进程集成方案与进度条优化技巧,帮助开发者规避界面卡顿、内存损坏等常见问题。
实现单芯片2400bps 音频编解码方案
终于按照朋友的需求,帮他开发了一款单芯片集音频采集编码传送并接收解码播放功能的方案,交给快递公司邮寄给远在郑州的他.整个项目从开始定型到现在一个样机送出,整整花了1个月时间,感觉挺有成就感,挺有意思,工作是辛苦的,结果却是快乐的.现在将这中快乐的的心情与大家分享一下. 真个项目用一颗主控搞定,ARM9的,200KBytes 片内RAM,主频可以跑到300MHz,64pin LQFP封装
C++运行时类型识别
C++ RTTI
【无人机路径规划】基于强化学习实现多无人机路径规划
【无人机路径规划】基于强化学习实现多无人机路径规划
5. C++ 运行时类型识别RTTI
作为C++开发人员,基本都知道dynamic_cast是C++中几个常用的类型转换符之一,其通过类型信息(typeinfo)进行相对安全的类型转换,在转换时,会检查转换的src对象是否真的可以转换成dst类型。这块逻辑比较绕,其实可以将关系理解为图上的一条条连接线,节点理解为类型信息,dynamic_cast的过程,就是判断有没有从src到dst有没有路径的过程。否则,在编译期就能获取其具体类型,甚至在某些情况下,可以对typeid()的结果直接进行替换。然后根据返回值的内容来判断结果,并进行相应的操作。
⭐️【2024年新版教程】vmware tools安装步骤(Windows、Linux、MacOS版本)
VMware Tools是VMware提供的一套实用工具,它可以增强虚拟机与宿主机之间的交互性能,如改进显示性能、优化鼠标和键盘性能、提供时间同步功能等。无论是在Windows、Linux还是MacOS虚拟机上,安装VMware Tools都可以提高虚拟机的使用体验。以上就是在不同操作系统上安装VMware Tools的步骤,希望对您有所帮助。
Devexpress16.2.6破解工具
Devexpress16.2.6破解工具Devexpress16.2.6破解工具Devexpress16.2.6破解工具Devexpress16.2.6破解工具
【C++】运行时类型识别
【C++】运行时类型识别
深度学习工具包 DeepLearningToolbox
深度学习工具包Deprecation notice.-----This toolbox is outdated and no longer maintained.There are much better tools available for deep learning than this toolbox, e.g. [Theano](http://deeplearning.net/software/theano/), [torch](http://torch.ch/) or [tensorflow](http://www.tensorflow.org/)I would suggest you use one of the tools mentioned above rather than use this toolbox.Best, Rasmus.DeepLearnToolbox================A Matlab toolbox for Deep Learning.Deep Learning is a new subfield of machine learning that focuses on learning deep hierarchical models of data.It is inspired by the human brain's apparent deep (layered, hierarchical) architecture.A good overview of the theory of Deep Learning theory is[Learning Deep Architectures for AI](http://www.iro.umontreal.ca/~bengioy/papers/ftml_book.pdf)For a more informal introduction, see the following videos by Geoffrey Hinton and Andrew Ng.* [The Next Generation of Neural Networks](http://www.youtube.com/watch?v=AyzOUbkUf3M) (Hinton, 2007)* [Recent Developments in Deep Learning](http://www.youtube.com/watch?v=VdIURAu1-aU) (Hinton, 2010)* [Unsupervised Feature Learning and Deep Learning](http://www.youtube.com/watch?v=ZmNOAtZIgIk) (Ng, 2011)If you use this toolbox in your research please cite [Prediction as a candidate for learning deep hierarchical models of data](http://www2.imm.dtu.dk/pubdb/views/publication_details.php?id=6284)```@MASTERSTHESIS\{IMM2012-06284, author = "R. B. Palm", title = "Prediction as a candidate for learning deep hierarchical models of data", year = "2012",}```Contact: rasmusbergpalm at gmail dot comDirectories included in the toolbox-----------------------------------`NN/` - A library for Feedforward Backpropagation Neural Networks`CNN/` - A library for Convolutional Neural Networks`DBN/` - A library for Deep Belief Networks`SAE/` - A library for Stacked Auto-Encoders`CAE/` - A library for Convolutional Auto-Encoders`util/` - Utility functions used by the libraries`data/` - Data used by the examples`tests/` - unit tests to verify toolbox is workingFor references on each library check REFS.mdSetup-----1. Download.2. addpath(genpath('DeepLearnToolbox'));Example: Deep Belief Network---------------------```matlabfunction test_example_DBNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit RBM and visualize its weightsrand('state',0)dbn.sizes = [100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);figure; visualize(dbn.rbm{1}.W'); % Visualize the RBM weights%% ex2 train a 100-100 hidden unit DBN and use its weights to initialize a NNrand('state',0)%train dbndbn.sizes = [100 100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);%unfold dbn to nnnn = dbnunfoldtonn(dbn, 10);nn.activation_function = 'sigm';%train nnopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.10, 'Too big error');```Example: Stacked Auto-Encoders---------------------```matlabfunction test_example_SAEload mnist_uint8;train_x = double(train_x)/255;test_x = double(test_x)/255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit SDAE and use it to initialize a FFNN% Setup and train a stacked denoising autoencoder (SDAE)rand('state',0)sae = saesetup([784 100]);sae.ae{1}.activation_function = 'sigm';sae.ae{1}.learningRate = 1;sae.ae{1}.inputZeroMaskedFraction = 0.5;opts.numepochs = 1;opts.batchsize = 100;sae = saetrain(sae, train_x, opts);visualize(sae.ae{1}.W{1}(:,2:end)')% Use the SDAE to initialize a FFNNnn = nnsetup([784 100 10]);nn.activation_function = 'sigm';nn.learningRate = 1;nn.W{1} = sae.ae{1}.W{1};% Train the FFNNopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.16, 'Too big error');```Example: Convolutional Neural Nets---------------------```matlabfunction test_example_CNNload mnist_uint8;train_x = double(reshape(train_x',28,28,60000))/255;test_x = double(reshape(test_x',28,28,10000))/255;train_y = double(train_y');test_y = double(test_y');%% ex1 Train a 6c-2s-12c-2s Convolutional neural network %will run 1 epoch in about 200 second and get around 11% error. %With 100 epochs you'll get around 1.2% errorrand('state',0)cnn.layers = { struct('type', 'i') %input layer struct('type', 'c', 'outputmaps', 6, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %sub sampling layer struct('type', 'c', 'outputmaps', 12, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %subsampling layer};cnn = cnnsetup(cnn, train_x, train_y);opts.alpha = 1;opts.batchsize = 50;opts.numepochs = 1;cnn = cnntrain(cnn, train_x, train_y, opts);[er, bad] = cnntest(cnn, test_x, test_y);%plot mean squared errorfigure; plot(cnn.rL);assert(er<0.12, 'Too big error');```Example: Neural Networks---------------------```matlabfunction test_example_NNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);% normalize[train_x, mu, sigma] = zscore(train_x);test_x = normalize(test_x, mu, sigma);%% ex1 vanilla neural netrand('state',0)nn = nnsetup([784 100 10]);opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samples[nn, L] = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.08, 'Too big error');%% ex2 neural net with L2 weight decayrand('state',0)nn = nnsetup([784 100 10]);nn.weightPenaltyL2 = 1e-4; % L2 weight decayopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex3 neural net with dropoutrand('state',0)nn = nnsetup([784 100 10]);nn.dropoutFraction = 0.5; % Dropout fraction opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex4 neural net with sigmoid activation functionrand('state',0)nn = nnsetup([784 100 10]);nn.activation_function = 'sigm'; % Sigmoid activation functionnn.learningRate = 1; % Sigm require a lower learning rateopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex5 plotting functionalityrand('state',0)nn = nnsetup([784 20 10]);opts.numepochs = 5; % Number of full sweeps through datann.output = 'softmax'; % use softmax outputopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex6 neural net with sigmoid activation and plotting of validation and training error% split training data into training and validation datavx = train_x(1:10000,:);tx = train_x(10001:end,:);vy = train_y(1:10000,:);ty = train_y(10001:end,:);rand('state',0)nn = nnsetup([784 20 10]); nn.output = 'softmax'; % use softmax outputopts.numepochs = 5; % Number of full sweeps through dataopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, tx, ty, opts, vx, vy); % nntrain takes validation set as last two arguments (optionally)[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');```[](https://bitdeli.com/free "Bitdeli Badge")
C++运行时类型识别RTTI
c++ RTTI(runtime type identification)
android 蓝牙通讯demo
android 下蓝牙通讯demo,实现了发现蓝牙,使能蓝牙,通过蓝牙发送消息。
NTscan扫描工具
ntscan是一个扫描器,可以扫描没有密码和弱密码的共享,先到配置文件中填写猜测的用户名和密码,扫描过程中右侧出现的是扫描日志。
C++小细节17-运行时类型识别
C++运行时类型识别两个运算符,dynamic_cast和typeid,会使用即可。
C++运行时类型识别(RTTI)
C++运行时类型识别(RTTI) 运行时类型识别RTTI(即Run-Time Type Identification) 主要通过typeid和dynamic_cast来实现
C++RTTI(运行时类型识别)
然而,并非任何时候都能定义一个虚函数。假设我们无法使用虚函数,则可以使用一个RTTI运算符。另一方面。
c++ RTTI 运行时类型识别
文章摘自 C++从入门到精通(第四版)清华大学出版社运行时类型识别(Run-time Type Identification,RTTI)是在只有一个指向基类的指针或引用时所确定的一个对象的类型。在编写程序的过程中,往往只提供了一个对象的指针,但通常在使用时需要明确这个指针的确切类型。利用RTTI就可以方便的获取某个对象指针的确切类型并进行控制。RTTI可以在程序运行时通过某一对象的指针确定该对象的类型。许多程序设计人员都使用过虚基类编写面向对象的功能。通常在基类中定义了所有子类的通用属性或行为。但有些时候子
C++运行时类型识别——RTTI
通过运行时类型识别——RTTI,程序能够使用基类的指针或引用来检索这些指针或引用所指对象的实际派生类类型:
550
7611
1253
952

被折叠的 条评论
为什么被折叠?



