bool to int conversion is not supported in j2c_array

[Wajihulhassan]

In my julia code, I have convert(Vector{Int64},(array1 .== var_tmp)). For expression (array1 .== var_tmp), it generates the following mmap

GenSym(154) = $(Expr(:mmap, Any[:(array1::Array{Int64,1})], [:x]" -> ""["(:x,:x,Int64)(:y,:y,Int64)(GenSym(0),GenSym(0),Bool)";"var_tmp",""]":\
(begin  # promotion.jl, line 225:
        GenSym(0) = x::Int64 === var_tmp::Int64::Bool
        (GenSym(0),)::Bool
    end::Bool)))

and for conversion part it generates

(Base.convert(Array{Int64,1},GenSym(154))::Array{Int64,1}

This Base.convert call is not handled in CGen as compiler throws following error while typecasting.

/home/whassan/.julia/v0.4/ParallelAccelerator/src/../deps/generated/cgen_output0.cpp(2100): error: no suitable user-defined conversion from "j2c_array<bool>" to "j2c_array<int64_t={lon\
g}>" exists
      GenSym19 = ( j2c_array< int64_t > )(GenSym17);

While GenSym17 is a bool j2c_array and GenSym19 is int64 j2c_array.

Thanks

[ninegua]

In general, we do not support convert call when compiling to C. Its semantics is complex, and Julia 0.4 also has difficulty inferring its return type.

We can write the same thing as 1 .* (array1 .== var_tmp), or (array1 .== var_tmp) .* 1. Both works in Julia 0.5 rc. However, the latter was failing in Julia 0.4 due to some inference issue, and is now fixed by CompilerTools commit e294daef.