Enumerationenumerations are user-defined types that contain a set of named integer constants called enumerators.Grammar
unscoped enum:
enum [identifier] [: Type]
{enum-list};
scoped enum:
enum [class|struct]
[identifier] [: Type]
{enum-list};
Forward Declaration of Enumerations (C++11):
enum a:int;//non-scoped enum must have type specified
enum CL Ass B; scoped enum defaults to int
enum class C:short;
ParametersIdentifierSpecifies
To give you Photoshop software users to detailed analysis of the design of the 11 flame metal word effect of the production of the tutorial.
Tutorial Sharing:
Final effect
1, a new 1024x768 pixel, resolution of 72 of the canvas, background filled with black. Right click on Figure 1 to select "Save Picture as", hold it to this machine, and then open with PS. The file is in PNG format, dragged to the new canvas with t
The analysis of this article is based on LLVM's libc++, not gun's libstdc++, because there are too many macros in the libstdc++ code, it looks like the egg hurts.
In multithreaded programming, there is a common scenario where a task needs to be executed only once. It provides convenient auxiliary class once_flag,call_once in c++11. Statement
First, take a look at Once_flag and Call_once's statement:
struct Once_flag
{
constexpr once_flag () noexc
The Sysmaster database is a pseudo database and is part of the Informix Dynamic Server (IDS) installation, showing the shared memory structure of the IDS server. This is an excellent tool for monitoring server status and performance. I've done a lot of speeches about this and I've written many articles.
IDS 11 (The Past code name is "Cheetah") adds a number of new features to the Sysmaster database. This column and future articles will provide exampl
Problem Description:
2010-2-25 found the video cannot access the situation, view Nginx error log found worker process 28541 exited on signal 11Alert, the process dies after rebuilding:
#more Error.log2010/02/25 15:35:48 [alert] 28537#0:worker process 28541 exited on signal 112010/02/25 15:35:49 [alert] 28537#0:worker process 28540 exited on signal 112010/02/25 15:35:49 [alert] 28537#0:worker process 28538 exited on signal 11
View DMESG also found an e
don't know why, this feature was introduced into the c++11. The use of the method is simple: Just add the final specifier after the function declaration.
The code basically does not change, except that the BASE::F1 () declaration is replaced with the final specifier. If the Sub::f1 () method is defined, a compile error is generated.
Author's opinion
Based on the author's personal understanding, this article puts the pure virtual function and the
name is returned, as shown in 4-27. ? Figure 4-27 returning the database name 9, known database name, you can query the MySQL information_schema database in the tables table, to get all the tables in the DVWA database. In the text box, enter 1 ' UNION SELECT 1,GROUP_CONCAT (table_name) from Information_schema.tables where table_schema= ' Dvwa ' #, Returns all the tables in the DVWA database, as shown in 4-28. ? Figure 4-28 returning a table in the database 10, it can be seen that the table in D
) {} // error if (nullprt) {} // error Nullpt r = 0 // error The above mentioned overload problem, when using nullptr, will call char*.void foo (int) "int" Endl;} void foo (char"pointer" Endl;} Foo (0); // calls foo (int) // calls Foo (char*) 3. Implementation of the analog nullptrSome compilers do not support c++11 's new keyword nullptr, and we can also simulate implementing a nullptr.Const classnullptr_t_t { Public: Templ
regular schedule every 30 secondsTimer.schedule (NewMyTask (List,lock), 0, 1000*30); } @Override Public voidcontextdestroyed (Servletcontextevent sce) {System.out.println ("Web Apps Off"); }}/*** @ClassName: mytask* @Description: Tasks to be performed regularly by timers *@author: Aloof and Pale wolf * @date: 2014-9-11 a.m. 12:02:36**/ classMyTaskextendsTimerTask {//a list collection that stores HttpSession PrivateListlist; //Store the locks passe
C++11 introduces a multivariate array of tuples, which is used to hold arrays of different data.There are two types of initialization methods:Tuple () constructorMake_tuple () Create functionThere are several commonly used functions as follows:Head () Gets the value of the first elementTail () Gets the value of all remaining elementsGetTuple_elementTuple_sizeIn addition about type:Auto automatic type deduction, which infers the data type of a variable
prompt whether to overwrite, and then think of the Linux alias mechanism:12alias cp= ' cp-i '3alias l.= ' ls-d. *--color=auto '4 Alias ll= ' ls-l--color=auto '5alias ls= ' ls--color=auto '6alias mv= ' Mv-i ' 7alias rm= ' echo * use more secure command '8 alias Which= ' Alias | /usr/bin/which--tty-only--read-alias--show-dot--show-tilde 'You can see that Linux executes the CP command when the default parameter is-I, modifying the default parameter to-F (dangerous, only for the purpose of the pr
Today, after dealing with the problem, you have nothing to do, and intend to practice shell scripting in Ubuntu in the virtual machine.Helpless, virtual machine system installed only VI, this editing software for us or is not accustomed to, so intends to install vim. All right, gossip a little.Install Vim:1. I am the virtual machine system to avoid trouble, directly switch the root user. Input: Apt-get install VIM-GTK command can be installed, if not the root user, add sudo in front of the comma
B are Used before their declarations.To solve this problem, C++11 introduced a feature called trailing return types. Using This feature, the previous program can be rewritten as follows:TemplateAuto Mul (t A, T B), Decltype (a*b) {return a*b;}We Specify the function return type after the declaration of parameter declarations. Composite symbol->decltype (T1+T2) is called a trailing return type. The Auto keyword is placed before the function identifier
= int to define type aliases, similar to typedef functionsL Template instantiation >> is used as an end-of-compliance methodL Use Auto to do dynamic type, the maximum application is to define iterator. and using auto-decorated functions can post the return type, you can define the return type directly after the functionL Hash_code is a new member of RttiL Decltype enables C + + to finally support the change of new types such as reflection, and it automatically removes the CV qualifierL for can b
, and when the + = string object is appended with the length of string.size ()C_STR () Data ()Note:The string object does not identify the end of the strings with a null character (null, ' \ s ')3. Range for (range for)//c++11 Addfor (range_declaration:range_expresssion)Loop_statement;Range_declaration: A variable declaration, which is an element or reference to a sequence of range_expression, usually using auto to detect its typeRange_expression: An
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