basic_dsp::try_vec!

macro_rules! try_vec {
    ( $ expr : expr ) => { ... };
}

Like try! but for operations returning a vector.

Operations which return a vector on success even return an error reason together with a vector on failure. So even if the operation has failed the vector can still be reused and thus memory allocation can be avoided. If this is undesired then this macro can be used instead of try! to just return the error reason.