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Comment by revelation | Hacker News Reader

constexpr isn't mean to replace the preprocessor. This will not compile for the same reason that

    if (false constexpr) { random gibberish }

will not compile, and that's a good thing. I think it would be odd to "hack" static_assert for this special case.

Opinions differ I guess. I would love it if

    if constexpr ( COND) { CODE };

would compile even if CODE only compiles when COND is true. There a lot of nice use cases for that, and that's how the static_if in D works.

You can still do this sort of stuff with template overloads, but it's much more cumbersome.

That's the case though, as long as CODE is syntactically correct. So this would compile:

  if constexpr (condition) {
    print("yes");
  }

While this wouldn't:

  if constexpr (condition) {
    print({
  }

At least that's my understanding.