Using new 0.6 type syntax without erroring out on older versions

[tlnagy]

Not sure whether I should open this here or elsewhere, but is there any mechanism for supporting the new where syntax from JuliaLang/julia#18457 on older versions of julia? Or at least stopping it from erroring out?

Currently, it looks like it comes up as a syntax error so throwing it inside of a if VERSION >= conditional doesn't help.

ERROR: LoadError: LoadError: syntax: missing comma or ) in argument list
 in include_from_node1(::String) at ./loading.jl:488 (repeats 2 times)
 in macro expansion; at ./none:2 [inlined]
 in anonymous at ./<missing>:?
 in eval(::Module, ::Any) at ./boot.jl:234
 in process_options(::Base.JLOptions) at ./client.jl:239
 in _start() at ./client.jl:318
while loading /home/travis/.julia/v0.5/FixedPointNumbers/src/ufixed.jl, in expression starting on line 54
while loading /home/travis/.julia/v0.5/FixedPointNumbers/src/FixedPointNumbers.jl, in expression starting on line 96
ERROR: LoadError: Failed to precompile FixedPointNumbers to /home/travis/.julia/lib/v0.5/FixedPointNumbers.ji.
 in compilecache(::String) at ./loading.jl:593
 in require(::Symbol) at ./loading.jl:422
 in include_from_node1(::String) at ./loading.jl:488
 in eval(::Module, ::Any) at ./boot.jl:234
 in process_options(::Base.JLOptions) at ./client.jl:239
 in _start() at ./client.jl:318
while loading /home/travis/.julia/v0.5/FixedPointNumbers/test/runtests.jl, in expression starting on line 1

PR in question here: JuliaMath/FixedPointNumbers.jl#62

[yuyichao]

Compat cannot help with syntax error in general.

[tlnagy]

What would be the best channel to raise this issue in then?

[yuyichao]

Use a typealias instead of the where syntax in JuliaMath/FixedPointNumbers.jl#62