forward_def!

forward_def.jl

using MLStyle: @switch
macro forward_def!(self_ann, expr, methods...)
    @switch self_ann begin
        @case :($self :: $t_base{$(t_args...)})
        @case :($self :: $t_base) && let t_args = [] end
    end
    t = if !isempty(t_args)
        :($t_base{$(t_args...)})
    else
        t_base
    end
    block = []
    for meth in methods
        push!(block, :($Base.@inline $meth($self::$t, args...;kwargs...) where {$(t_args...)} = $meth($expr, args...; kwargs...)))
    end
    esc(Expr(:block, block...))
end