Multiple dispatch with more than 4 methods blocks type inference

[jling]

I believe discussion in this post can answer you question:

Unstable type with dispatch by Val{:X}() with 5 functions

When i use following code i have no problems with types using LinearAlgebra, BlockDiagonals function f1(x::Vector{T}, ::Int, ::Val{:A}) where T Diagonal(x) end function f1(x::Vector{T}, i::Int, ::Val{:B}) where T Diagonal(x .* i) end function f1(x::Vector{T}, ::Int, ::Val{:C}) where T Diagonal(x) end function f1(x::Vector{T}, ::Int, ::Val{:D}) where T Diagonal(x) end function f2(x1, x2, a, b) x = Vector{Matrix}(undef, 2) x[1] = f1(x1, 2, Val{a}()) x[2] = f1(x2, 3, Va…

the idea is that

@schaerfo

in performance-critical sections

won’t have 4+ methods to look up, or at least the trade-off is the same at that point.