Fix det() return type for dimension N >= 4

Author: c42f

src/det.jl

@@ -24,12 +24,13 @@ end
     return vecdot(x0, cross(x1, x2))
 end
 
-@generated function _det{S,T}(::Size{S}, A::StaticMatrix{T})
+@generated function _det{S}(::Size{S}, A::StaticMatrix)
     if S[1] != S[2]
         throw(DimensionMismatch("matrix is not square"))
     end
     return quote # Implementation from Base
         @_inline_meta
+        T = eltype(A)
         T2 = typeof((one(T)*zero(T) + zero(T))/one(T))
         if istriu(A) || istril(A)
             return convert(T2, det(UpperTriangular(A))) # Is this a Julia bug that a convert is not type stable??

test/det.jl

@@ -7,6 +7,7 @@
     #triu/tril
     @test det(@SMatrix [1 2; 0 3]) === 3
     @test det(@SMatrix [1 2 3 4; 0 5 6 7; 0 0 8 9; 0 0 0 10]) === 400.0
+    @test @inferred(det(ones(SMatrix{10,10,Complex{Float64}}))) == 0
 
     # Unsigned specializations
     @test det(@SMatrix [0x00 0x01; 0x01 0x00])::Int8 == -1