Make function nothrow

[ref2401 via Digitalmars-d-learn]

There are functions in Phobos that do not throw but they are not 
marked as `nothrow`.
When I need to call them from my `nothrow` code I do this:
void foo() { /* I won't throw, honestly. */ }

void bar() nothrow {
        scope(failure) assert(false);
        foo();
}

The question is: Is it ok to do such thing or should I just stick 
with try {} catch() {}?
Thank you.