Yes this helps specifically when passing functions as pointers or something like std::function (edit: or overriding methods), it will at least inform the developer that they need to add noexcept to the function declaration if they want to use it there, and hopefully due to that they recursively audit the function body and anything it calls for exceptions. And hopefully all future developers also notice the noexcept and keep up the practice. But it changes nothing about checking plain function calls. So I think adding this to the function type helps some cases but still does not move noexcept toward the behavior most people want/expect.

This just feels important to point out because this feature is 15 years old and still commonly misunderstood, and each time people are wanting the same thing (actual compile-time prevention of `throw`) which it is not.

Edit: OK I finally just went and tried it on godbolt.org. C++17 GCC, Clang, and MSVC all give 1 warning on this code for `bar` and that's all.

  void canthrow() {
    throw 42;
  }
  
  void foo() noexcept {
    canthrow();
  }
  
  void bar() noexcept {
    throw 42;
  }