Cxx.jl calling the Julia error function from C++

General Usage
1

I am trying to propagate an error from C++ to Julia. From the Cxx.jl documentation, I found (which works fine):

julia> cxx"“”
void testJuliaPrint() {
$:(println(“\nTo end this test, press any key”)::Nothing);
}
“”"

Trying the same with the Julia error() function:

julia> cxx"“”
void testJuliaError() {
$:(error(“ERROR”)::Nothing);
}
“”"

Results in (which I am not competent to interpret):

ERROR: Inferred Union or abstract type Union{} for return value of lambda
Stacktrace:
[1] error(::String) at ./error.jl:33
[2] cpptype(::Cxx.CxxCore.ClangCompiler, ::Type{getfield(Main, Symbol(“##42#43”))}) typetranslation.jl:302
[3] ssv(::Cxx.CxxCore.ClangCompiler, ::Any, ::Cxx.CxxCore.CppPtr{Cxx.CxxCore.CxxQualType{Cxx.CxxCore.CppBaseType{Symbol(“clang::DeclContext”)},(false, false, false)},(false, false, false)}, ::Int64, ::Base.GenericIOBuffer{Array{UInt8,1}}, ::Dict{Nothing,Nothing}) cxxstr.jl:56
[4] ssv(::Cxx.CxxCore.ClangCompiler, ::Any, ::Cxx.CxxCore.CppPtr{Cxx.CxxCore.CxxQualType{Cxx.CxxCore.CppBaseType{Symbol(“clang::DeclContext”)},(false, false, false)},(false, false, false)}, ::Int64, ::Base.GenericIOBuffer{Array{UInt8,1}}) at cxxstr.jl:40
[5] top-level scope at cxxstr.jl:641

Actually, println() is the only function I have found to be callable from C++. Any ideas how to propagate an error condition from C++ to Julia ?

2

X-ref: Calling Julia Base.error() from C++ · Issue #433 · JuliaInterop/Cxx.jl · GitHub

what do you mean? could you post those failed examples?

julia> using Cxx

julia> cxx"""
          float cxxsin() {
              return $:(sin(x)::Float32);
          }
       """
true

julia> x = 0.5f0
0.5f0

julia> @cxx cxxsin()
0.47942555f0