Multiple namespace declaration in C++

Question

Is it legal to replace something like this:

namespace foo {
   namespace bar {
      baz();
   }
}

with something like this:

Answer 1

For anyone wondering, the form namespace foo::bar is supported since C++17. References:

• http://en.cppreference.com/w/cpp/language/namespace
• http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4230.html