Why can I call a non-constexpr function inside a constexpr function?
The program is ill-formed and requires no diagnostic according to the C++11 draft standard section 7.1.5 The constexpr specifier paragraph 5 which says: For a constexpr function, if no function argument values exist such that the function invocation substitution would produce a constant expression (5.19), the program is ill-formed; no diagnostic required. and provides the … Read more