[conbandit]

Output is:

  vector<int> v{3} size() 1
  vector<string> v{3} size() 3
  vector<int> v{0} size() 1
  terminate called after throwing an instance of 
  'std::logic_error'
    what():  basic_string::_M_construct null not valid
  Aborted (core dumped)

Can anyone explain why there's a logic error?

[clord]

I'd guess it chooses the implicit string(const char*) constructor and then feeds it a nullptr. I think the plan is to get rid of this in the future with the new nullptr_t/nullptr mechanism, but for now we're stuck with it.

[steveklabnik]

that's what /r/cpp says it is

[timriederj]

Constructing with {} uses an initializer list and the () is constructing by setting the size. See more details here: https://stackoverflow.com/questions/33185543/delegating-cons...