Inconsistent Matrix creation with tuples

[Jackels]

Julia v0.6

a::Int64 = 5
b::Tuple{Int64, Int64} = (a, a)
Matrix{Int64}(b)

This code works, but if you replace all instances of Int64 with Int32 it does not work anymore.

ERROR: MethodError: Cannot `convert` an object of type Tuple{Int32,Int32} to an object of type Array{Int32,2}
This may have arisen from a call to the constructor Array{Int32,2}(...),
since type constructors fall back to convert methods.

But if you write it a bit different

a::Int64 = 5
Matrix{Int64}(a, a)

this will work with either Int32 or Int64.

I think my first sample should work with any integer-version.

[fredrikekre]

Closing in favor of #23029. See also #23032, #17372 (comment)