参数通过变量x初始化, x是个左值. forwarding reference参数通过左值初始化,所以参数变成了一个左值引用,确切说是int&。 The comment next to the declaration of f should now be clear: whether param’s type is an lvalue reference or an rvalue reference depends on what is passed when f is called. ...
简单地说,能取到地址的(在内存中,而不是在寄存器中)就是右值,其余都是左值。 Rvalue Reference右值引用 当赋值操作的右边是右值(rvalue),左边的对象不需要特意分配内存去存放这个拷贝(copy),而可以搬移(move)右边对象的资源。 用于解决不必要的拷贝和实现完美转发(perfect forwarding)。 Move Semantics移动语义 move...
断言,是宏,而非函数。assert 宏的原型定义在<assert.h>(C)、<cassert>(C++)中,其作用是如果它的条件返回错误,则终止程序执行。可以通过定义NDEBUG来关闭 assert,但是需要在源代码的开头,include <assert.h>之前。 使用 代码语言:javascript 代码运行次数:0 运行 AI代码解释 #defineNDEBUG// 加上这行,则 asser...
If C-BSRs use different BS_interval or holdtime values or if BS_interval must is larger than the holdtime, the BSR changes frequently, causing multicast forwarding errors. Example # In the PIM-IPv6 view, set the timeout interval during which the C-BSR waits for the Bootstrap message to...
mac-forced-forwarding static-gateway mac-forced-forwarding user-detect transparent mac-forced-forwarding user-isolate-port reset mac-forced-forwarding user Traffic Suppression and Storm Control Configuration Commands ARP Security Configuration Commands DHCP Snooping Configuration Commands IP Source Guard Co...
<typename T>typename remove_reference<T>::type&& move(T&& t){return static_cast<typename remove_feference<T>::type&&>(t);}std::move 的工作原理：当传入右值时，例如 string(“test”)，其工作流程如下推导出来的类型 T 为 string因此，remove_reference 实例化为 stringremove_reference 为 string...
和下面的 absl::variant<UnknownAction, RouteAction, NonForwardingAction> action; 在这种语法中,默认生成的构造函数应该是能够初始化 seconds 和nanos 的。后面这一行会报 /usr/include/c++/9/type_traits:883:12: error: default member initializer for ‘grpc_core::XdsApi::Duration::seconds’ required bef...
The set forward synchronization timer command sets the scheduled synchronization time of forwarding entries. The undo set forward synchronization timer command restores the default settings. The set forward synchronization disable command disables scheduled synchronization of forwarding entries. By default, sche...
This action only takes effect in Layer 3 forwarding. Example # Configure two next hop IP addresses in the traffic behavior b1: 13.1.42.1 and 32.1.1.2. <HUAWEI> system-view [~HUAWEI] traffic behavior b1 [*HUAWEI-behavior-b1] redirect load-balance nexthop 13.1.42.1 32.1.1.2Related...
return[superforwardingTargetForSelector: aSelector]; } 毕竟消息转发要耗费更多时间,抓住这次机会将消息重定向给别人是个不错的选择,不过千万别返回 self ,因为那样会死循环。 6.2 转发 当动态方法解析不作处理返回 NO 时,消息转发机制会被触发,这时forwardInvocation: 方法会被执行,我们可以重载这个方法来定义我们...