Type Expectation Documentation

[BenjaminHolland]

Since there's so much use of auto and variable length argument lists, It's quite difficult to understand both what types the operators expect,whether or not they expect template parameters, and which types they return.

For example buffer and window would seem on the surface to be quite similar, but one returns an observable<std::vector> and the other returns an observable<observable>. These are not documented. Further, the compiler errors generated for not getting these things right are not helpful. In the same case, I was told that "Delegate[largehash]" did not have a member "on_error".

[gchudnov]

Agreed, the code is not explicit :(
At the moment the best way is to look at documentation and examples.