```
julia> mod(π,ℯ)
0.423310825130748
julia> mod(√2,π)
1.4142135623730951
julia> mod(π,π)
ERROR: mod not defined for Irrational{:π}
Stacktrace:
[1] error(::String, ::String, ::Type) at ./error.jl:42
[2] no_op_err at ./promotion.jl:420 [inlined]
[3] mod(::Irrational{:π}, ::Irrational{:π}) at ./promotion.jl:440
[4] top-level scope
julia> versioninfo()
Julia Version 0.7.0-DEV.3686
...
```

Two identical irrational numbers don’t parse well by `mod()`

. Is this a bug or by design?