particle physics - Could $p+prightarrow pi^++d$ occur via the weak interaction?

Consider the reaction $p+p\rightarrow \pi^++d$ (where $d$ is deuteron) which occurs via the strong interaction. From what I have read (in e.g. Williams 1992 (p326)) it would seem there is nothing preventing this from happening via the weak interaction (or for that matter the electromagnetic).

Is this the case? i.e. can $p+p\rightarrow \pi^++d$ occur solely through the weak interaction? And if not how do we know it must be via the strong (without looking at e.g. cross-sections)?

Edit

Just for completeness the only quark changes that occur are the creation of $d$ and $\bar d$ ($d$ here is the down quark).