Depends on if you need to gracefully handle malloc failures or not. Otherwise any write operation on an STL type (like appending to a string) will potentially throw an exception that you need to care about.

In the C world this is extremely arduous since need to bubble the allocation-failure down through every level of code, adding cleanup to just about every function call. If you're using C++ and RAII you can just catch std::exception in one place to cover a huge number of places that an allocation can fail.