https://www.geeksforgeeks.org/builtin-functions-gcc-compiler/
__builtin_clz(x): This function is used to count the leading zeros of the integer. Note : clz = count leading zero’sExample: It co...
public继承普通类，子类中可以直接用父类的protected和public成员
class base
{
protected:
int a;
typedef int value_type;
};
class child : public base
{
public:
void set(int o) { a = o; ...
