Be aware of this if your return-object has RAII semantics that destroy the coroutine frame

when

A Trivial Iterator may have a singular value,

The C++11 initializer list rule

Class hierarchies are used to organize related classes into hierarchical structures.

accessed through a pointer member.

Singletons are basically complicated global objects in disguise.

Nottied to threading facilities. It is possible to implement efficient callback-based network programs on platforms that have no thread support.

来看下面这一个例子

Precompile code

tag dispatching

context switch function

a newly created execution context

This kind of coroutine

对于c++，在离开现场时不能提前析构掉那些没有被捕获的变量

我们知道有很多人喜欢直接在栈上申请一个64kb的char数组做缓冲区，

In the REPL, you can then enter and run lines of code one at a time.

如果改用协程，生产者生产消息后

列表生成式

氢氯噻嗪等

Because spdlog is header-only, building shared libraries and using it in a main program will not share the registry between them.

In less formal terms,

reports a compile-time error for the same reason on compilers that support relaxed constexpr

std::launch::deferred：延迟加载方式创建线程。调用async时不创建线程，直到调用了future的get或者wait时才创建线程。

indicates that the actual data exchange is wanted

-s

It compiles those sources using Visual Studio 2017, or Visual Studio 2015 if 2017 is not installed

SQLITE_INCLUDE_DIR string Path to SQLite 3 include directory where CMake should look for sqlite3.h header. SQLITE_LIBRARIES string Full paths to libraries to link SOCI against to enable the backend support.

When the Inherit from parent or project defaults check box is selected and you add a new value, it is appended to any values that are currently being inherited. If you clear the check box, your new value replaces the inherited values.

系统中CPU的数量

streambuf类提供了一个rdbuf成员函数可以用来读取内部用来保存缓冲数据的私有成员。

static DurationTimevalToDuration(const timeval & value)

add another phone number to the message which you can then edit (repeated scalar types have an add_ that just lets you pass in the new value).

checks if all the required fields have been set.

There are also has_ methods for each singular (required or optional) field

The stub forwards all calls to an RpcChannel, which in turn is an abstract interface that you must define yourself in terms of your own RPC system.

命令模式（Command Pattern）是一种数据驱动的设计模式，它属于行为型模式。请求以命令的形式包裹在对象中，并传给调用对象。调用对象寻找可以处理该命令的合适的对象，并把该命令传给相应的对象，该对象执行命令。

凡是能够取地址的可以称之为左值，反之称之为右值

说起来非常简单：凡是真正的存在内存当中，而不是寄存器当中的值就是左值，其余的都是右值。其实更通俗一点的说法就是：凡是取地址（&）操作可以成功的都是左值，其余都是右值。

if your code seems unnecessarily convoluted or overly cluttered with try blocks,

Fortunately there is plenty of wisdom and insight on the proper use of exceptions

you need to know when a condition should be reported via return-code and when it should be reported via an exception.

The encoding of calendar time in std::time_t is unspecified, but most systems conform to POSIX specification and return a value of integral type holding the number of seconds since the Epoch. Implementations in which std::time_t is a 32-bit signed integer (many historical implementations) fail in the year 2038.

signal-and-slot

The purpose it to keep this as general as possible on the caller side.

call "%VS140COMNTOOLS%..\..\VC\vcvarsall.bat" x64

在导出函数的声明时需要有_declspec(dllexport)关键字

note that we now need to install the headers as well, because they must be available for your installed target.

要把一个DLL文件映射到进程的地址空间，有两种方法：静态链接和动态链接的LoadLibrary或者LoadLibraryEx。

all global objects (including static members of classes) will be constructed

There are many problems with #pragma setlocale.

change the source character set for a file as it is being parsed.

what is the current code page of the system we are compiling on

Here are some examples how to specify the character sets using gcc

ls cert:CurrentUserMy

有没有权限更高的变量，有，那就是：选项Constant，常量一旦声明，不可修改

但是可以通过删除变量，再重新创建变量更新变量内容。

通过cmd进入cmd控制台输入ping发现执行的不是ping命令，而是直接运行ping.bat ，也就是说可以通过.bat 覆盖cmd命令。

有一份公共代码或数据需要所有分支共享，如果存储在普通的目录下，切分支之后各个分支该目录可能会出现差异，为了避免这种差异，应该使用 SVN 的 externals 属性，确保在任意分支下的更改在所有分支下都能够生效。

time_point必须要clock来计时

Duration

通过duration_cast<>()来将当前的时钟周期转换为其它的时钟周期

hz30

它们的定义如下：

typedef duration<long long, nano> nanoseconds;
typedef duration<long long, micro> microseconds;
typedef duration<long long, milli> milliseconds;
typedef duration<long long> seconds;
typedef duration<int, ratio<60> > minutes;
typedef duration<int, ratio<3600> > hours;

为什么一定要用三个随机数，来生成"会话密钥"，

The reply and status are ready once the tag

bidirectional streaming RPC

系统隐式调用析构函数的时候，会加入释放栈内存的动作

a single stream for a single client.

在子模块上工作

whose content is stored as contiguous byte sequence

如果 locale 是 NULL 或空字符串 ""，则区域名称将根据环境变量值来设置，其名称与上述的类别名称相同。

locale-sensitive C library functions

当 locale 为 "" 时，根据环境的设置来设定 locale，检测顺序是：环境变量 LC_ALL，每个单独的locale分类LC_*，最后是 LANG 变量。

MeyersSingleton meyers2 = meyers;MeyersSingleton meyers3(meyers);

拷贝构造函数（和拷贝赋值操作符）必须禁止

在单线程下(或者是C++0X下)是没任何问题的，但在多线程下就不行了

系统发现32位的程序