To force checks at compile time the construction from the chrono type needs to be consteval. There is no way around it.

consteval explicit delay_t(duration<int64_t, std::nano> delay) : delay_t {wrapped_{delay}} {}; 

To allow also runtime construction we needs an alternative way to construct delay_t. We can for example use a static method runtime that is constexpr.

constexpr static auto runtime(duration<int64_t, std::nano> delay) -> delay_t { return delay_t {wrapped_ {delay}}; } 

As this method needs to construct delay_t in some different way, we need a second non-consteval constructor. But as we already have one for chrono, we need to introduce a private wrapper type:

private: struct wrapped_ { duration<int64_t, std::nano> value; }; constexpr delay_t(wrapped_ delay) : value {delay.value} { if (value != delay.value) { throw std::runtime_error("delay cannot be represented."); } }; 

Using delay_t now enforces compile-time checks by default:

foo(delay_t {1s}); foo(delay_t {10s}); // gives compile time error foo(delay_t::runtime(10s)); // gives a runtime error 

Full example on godbolt

To force checks at compile time the construction from the chrono type needs to be consteval. There is no way around it.

consteval explicit delay_t(duration<int64_t, std::nano> delay) : delay_t {wrapped_{delay}} {}; 

To allow also runtime construction we needs an alternative way to construct delay_t. We can for example use a static method that is constexpr.

constexpr static auto runtime(duration<int64_t, std::nano> delay) -> delay_t { return delay_t {wrapped_ {delay}}; } 

As this method needs to construct delay_t in some different way, we need a second non-consteval constructor. But as we already have one for chrono, we need to introduce a private wrapper type:

private: struct wrapped_ { duration<int64_t, std::nano> value; }; constexpr delay_t(wrapped_ delay) : value {delay.value} { if (value != delay.value) { throw std::runtime_error("delay cannot be represented."); } }; 

Using delay_t now enforces compile-time checks by default:

foo(delay_t {1s}); foo(delay_t {10s}); // gives compile time error foo(delay_t::runtime(10s)); // gives a runtime error 

Full example on godbolt