Inconsistency converting multi-dimensional array literals

[ssfrr]

It looks like these two 2D array literals produce the same array, but when prepending the 2nd syntax with Float32 to force the type I get a conversion error.

julia version 0.3.0-prerelease+604

julia> [1 2 3; 3 4 5]
2x3 Array{Int64,2}:
 1  2  3
 3  4  5

julia> [[1 2 3]; [3 4 5]]
2x3 Array{Int64,2}:
 1  2  3
 3  4  5

julia> Float32[1 2 3; 3 4 5]
2x3 Array{Float32,2}:
 1.0  2.0  3.0
 3.0  4.0  5.0

julia> Float32[[1 2 3]; [3 4 5]]
ERROR: no method convert(Type{Float32}, Array{Int64,2})
 in setindex! at array.jl:413
 in getindex at array.jl:153

[simonster]

Somewhat related to #3737

[JeffBezanson]

The problem is that [ ] performs concatenation of arrays, while T[] constructs arrays where every element is of type T, and no concatenation is done. Most of us want to get farther from the concatenating behavior, but I'm not sure what T[a; b] should do.

[JeffBezanson]

Closing as dup of #3737.