c++ - How to initialize a union of pointers to nullptr? -

assume have c++ class this:

class container { private:   union {     foo* foo;     bar* bar;   } mptr; };

this class constructed on stack. i.e. won't newed, can't declare zeroing operator new.

can use initializer in constructor set mptr nullptr somehow?

container()  : mptr(nullptr) { }

does not compile. not adding dummy union member of type nullptr_t.

container()  : mptr.foo(nullptr) { }

doesn't compile, either.

use aggregate initialization, example:

container() : mptr { nullptr } { }

i don't posting links, here run through of technique.

Cap