Ccall c++ sort vector of String

New to Julia
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First you need to create the C++ file that does what you want and expose it to Julia. Let’s call it sort.cpp:

#include "jlcxx/jlcxx.hpp"

void sort_string(std::vector<std::string>& v)
{
    std::sort(v.begin(), v.end());
}

JLCXX_MODULE define_julia_module(jlcxx::Module &mod)
{
    // This exposes the function `sort_string` to the module.
    mod.method("sort_string", &sort_string);
}

Now, you need to compile it. In my machine, I can run the following command:

clang++ \
    --std=c++17 -shared -undefined dynamic_lookup \
    -o libsort.dylib \
    -I../../.julia/artifacts/c598c0cf1873e3cacf620287193aaf12bf5f8ace/include/ \
    -I/Applications/Julia-1.7.app/Contents/Resources/julia/include/julia -L/Applications/Julia-1.7.app/Contents/Resources/julia/lib/Julia \
    sort.cpp

In your case, you will need to change the paths. After that, I get the wrap library libsort.dylib.

Now, we need to create a module in Julia that contains the wrapped functions. This is very simple and we will handle the type conversions between Julia arrays and std::vector internally:

module Sort
    using CxxWrap

    @wrapmodule("libsort")

    function sort(v::Vector{String})
        # We need to convert the Julia vector into the
        # `std::vector<std::string>`, which is already wrapped by CxxWrap.
        svec = StdVector(CxxRef.(StdString.(v)))

        # Call the function that will sort the vector using `std::sort`.
        sort_string(svec)

        # Now, just convert the sorted vector back to a Julia array.
        return String[svec...]
    end

    function __init__()
        @initcxx
    end
end

Finally, you just need to include this module and the sort can be performed as follows:

julia> v = ["C", "X", "X", "W", "R", "A", "P"]
7-element Vector{String}:
 "C"
 "X"
 "X"
 "W"
 "R"
 "A"
 "P"

julia> Sort.sort(v)
7-element Vector{String}:
 "A"
 "C"
 "P"
 "R"
 "W"
 "X"
 "X"

Of course this example is the simplest way I found to perform what you described. There is probably 100 other alternatives much better and faster.

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