Rewritten mates function in old Ecosystem.

Author: janfrancu

src/Ecosystem.jl

@@ -16,12 +16,8 @@ function EcosystemCore.eat!(s::Animal{Sheep}, m::Plant{Mushroom}, w::World)
     m.size = 0
 end
 
-for S in (Sheep, Wolf)
-  @eval begin
-        EcosystemCore.mates(a::Animal{$S,Female}, b::Animal{$S,Male}) = true
-        EcosystemCore.mates(a::Animal{$S,Male}, b::Animal{$S,Female}) = true
-  end
-end
+EcosystemCore.mates(::Animal{S,Female}, ::Animal{S,Male}) where S<:Species = true
+EcosystemCore.mates(::Animal{S,Male}, ::Animal{S,Female}) where S<:Species = true
 EcosystemCore.mates(a::Agent, b::Agent) = false
 
 function simulate!(world::World, iters::Int; cb=()->())