问Ctor不允许返回类型

EN

// vvv return type vvv
struct { /* stuff */ } foo(void)
{
}

struct B
{
    int* a;
    B(int value):a(new int(value))
    {   }
    B():a(nullptr){}
    B(const B&);
}; // end class definition

// ah, no return type
B::B(const B& pattern)
{

}

a.cpp:1: error: new types may not be defined in a return type
a.cpp:1: note: (perhaps a semicolon is missing after the definition of 'B')
a.cpp:5: error: return type specification for constructor invalid

struct B {
...
} x, y, z;