@SVector rand and randn don't work with rng argument

[tpapp]

Eg

julia> @SVector randn(Base.Random.GLOBAL_RNG, 5)
ERROR: TypeError: Type: in parameter, expected Type, got MersenneTwister

I looked at the macro and realized it may be tricky to do make this work, but a performant workaround would also help.

[andyferris]

True, the macros by there nature are a bit of a "hack" and it's hard to cover every use case.

IIRC you can do randn(GLOBAL_RNG, SVector{5}). We should be able to support randn(GLOBAL_RNG, Size(5)) or something along those lines.

[c42f]

I don't think we'll fix this with the macros; there's just no way to make the macro interface generalize to the many expressions people might want to use with it. In fact, we might eventually deprecate the macro interface entirely.