std::is_enum 定义于头文件<type_traits> template<classT> structis_enum; (C++11 起) 检查T是否为枚举类型。若T为枚举类型,则提供等于true的成员常量value。否则,value等于false。 添加is_enum或is_enum_v(C++17 起)的特化的程序行为未定义。 模板形参 T-要检查的类型 辅助变量
*key[29]={"main","int","if","else","for","while","do","return","break","continue","float","double","char","void","long","short" ,"switch","case","default","goto","auto","static","register","extern","struct","union","enum","typedef","sizeof"}; //1.加入其他关键字...
cout 用于在计算机屏幕上显示信息,是C++中iostream 类型的对象,C++的输出是用“流”(stream)的方式实现的,流运算符的定义等信息是存放在C++的输入输出流库中的,因此如果在程序中使用cout和流运算符,就必须使用预处理命令把头文件stream包含到本文件中,即 < iostream > 库,该库定义的名字都在命名空间 std 中,所...
std::cout< 对于结构体变量,访问其中的成员采取“结构体变量.成员”的形式;而对于结构体指针,访问它所指向的结构体变量中的成员,则采取“结构体指针->成员”形式。 二、联合体类型 1、什么是联合体 联合体也是一种自定义的复合类型,它可以包含多个不同类型的变量。这些变量在内存当中共用一段空间。这段空间的si...
using namespace std;int nFlag = 0; //用移位表示各个枚举的开关 typedef enum { TYPEA, //A开启，则nflag为1=0x00000001 TYPEB, //B开启，则nflag为2=0x00000010 TYPEC, //C开启，则nflag为4=0x00000100 TYPED, //D开启，则nflag为8=0x00001000 TYPENUM //枚举最大值，计数用 }EMTypeNum;v...
C/C++ : converting std::string to const char* I get the error : left of '.c_str' must have class/struct/union type is 'char *' C# to C++ dll - how to pass strings as In/Out parameters to unmanaged functions that expect a string (LPSTR) as a function parameter. C++ int to str...
enum sc_time_unit { SC_SEC, SC_MS, SC_US, SC_NS, SC_PS, SC_FS, SC_AS, SC_ZS, SC_YS }; 与wait配合使用 void simple_process_ex::my_thread_process() { // std::cout << "my_thread_process executed within " << name() << std::endl; wait(10, SC_NS); std::cout <<...
typedef enum memory_order { memory_order_relaxed, memory_order_consume, memory_order_acquire, memory_order_release, memory_order_acq_rel, memory_order_seq_cst } memory_order; std::memory_orderspecifies how memory accesses, including regular, non-atomic memory accesses, are to be ordered around...
static BOOL WINAPI EnumPhyCallback( const void *pvSystemStore, DWORD dwFlags, LPCWSTR pwszStoreName, PCERT_PHYSICAL_STORE_INFO pStoreInfo, void *pvReserved, void *pvArg); static BOOL WINAPI EnumSysCallback( const void *pvSystemStore, DWORD dwFlags, PCERT_SYSTEM_STORE_INFO pStore...
}; // as above int main() { // since C++11, use std::underlying_type to determine the underlying type of an enum typedef std::underlying_type< settings::flags> ::type flags_t; auto val = settings::bit1; switch (static_cast< flags_t> (val)) { case settings::bit0: break; ...