How to assert that a constexpr if else clause never happen? : <p>I want to raise a compile time error when non of the constexpr if conditions is true eg:</p>

<pre><code>if constexpr(condition1){
    ...
} else if constexpr (condition2) {
   ....
} else if constexpr (condition3) {
  ....
} else {
    // I want the else clause never taken. But I heard the code below is not allowed
    static_assert(false);
}

// I'd rather not repeat the conditions again like this:
static_assert(condition1 || condition2 || condition3);
</code></pre>
