Working on 0.5.0-dev+2422: julia> type SomeCallBack z::Int end
julia> (_::SomeCallBack)(c) = _.z + c julia> s = SomeCallBack(24) SomeCallBack(24) julia> s(10) 34 julia> @code_llvm s(10) define i64 @julia_SomeCallBack_23730(%jl_value_t*, i64) #0 { top: %2 = bitcast %jl_value_t* %0 to i64* %3 = load i64, i64* %2, align 16 %4 = add i64 %3, %1 ret i64 %4 } I tried various combos with parametric types to no avail.