Allow returning Tuples from instructions

[ljiatu]

Hi! From looking at the IDL, it seems like returning Tuples from instructions isn't supported yet because the returns section is missing. The program compiles and runs fine, but the client wouldn't be able to get the return value. We are currently using custom structs to get around this, but wondering if there is any plan to support Tuples.

Thanks!

[acheroncrypto]

Regular tuples are not supported, not just returning them. It's almost always preferred to use named structs for public data because it makes it easier to understand the type and allows more discoverability.

It's close to impossible to tell what (u64, u64, u32, u32) means without looking at the source code. In contrast, named structs remove a lot of the mental overhead by self-describing the fields.