How to pass List<int> from C# to C++ CLi?

Question

I am beginner in C language family...

So, problem is - in my solution I have a repo (wrote in C#) that store List<int> , also I have an engine that (wrote in C++). So, I need pass List from C# implementation to C++ CLI for executing...

As far as I understood problem is C++ know how to work with std::vector and C# know how to work with List and I need somehow convert List to vector...

How to do it?

Any assumption appropriate.

EDIT

Sorry for misunderstanding, but my CLI works as a mapper for pure C++ implementation. So, as far as I understood from C# I need to pass my List to C++ CLI , C++ CLI will convert a List to vector and invoke another C++ file with pure C++ implementation.

This is my solution

h file using namespace System; using namespace System::Collections::Generic;

//forward declaration 
class MathCore;

namespace MathCore_CLI_namespace
{
public ref class MathCore_CLI
{
public:
    MathCore_CLI();
    ~MathCore_CLI();


    int computeMulPlusVals(List<int>^ list_first, List<int>^ list_second);
    //int computeMulPlusVals(std::vector<int> vect_first, std::vector<int> vect_second);

private:
    MathCore * m_pMathCore;
};
}

cpp file

#include "stdafx.h"
#include "MathCore_CLI.h"
#include "..\Engine\MathCore.h"
#include <iostream>
#include <array>
using namespace System;
using namespace System::Collections::Generic;

namespace MathCore_CLI_namespace
{
const int size = 5;
int count = 0;
int arrayVal[size];

MathCore_CLI::MathCore_CLI()
{
    m_pMathCore = new MathCore();
}

MathCore_CLI::~MathCore_CLI()
{
    delete m_pMathCore;
}



int computeMulPlusVals(List<int>^ list_first, List<int>^ list_second)
{
    return 0;
}
}

Error

What am I doind wrong?

Answer 1

C++ CLI directly supports List and you don't need a conversion. Here is a typical signature.

private: System::Void FooMethod( System::Collections::Generic::List<Int32>^ list )

Besides, In your updated question, you have a linker error.

Open C++ project properties, Find Linker and then Input. Add the location to your (EngineLib_Cli.dll) Library there

Answer 2

Also I found more optimized solution

int MathCore_CLI::computeMulPlusVals(array<int>^ arr_first, array<int>^ arr_second)
{
    auto vec_first = std::vector<int>(arr_first->Length);
    cli::pin_ptr<int> pPinnedFirst = &arr_first[0];
    memcpy(vec_first.data(), pPinnedFirst, arr_first->Length * sizeof(int));

    auto vec_second = std::vector<int>(arr_second->Length);
    cli::pin_ptr<int> pPinnedSecond = &arr_second[0];
    memcpy(vec_second.data(), pPinnedSecond, arr_second->Length * sizeof(int));

    return m_pMathCore->computeMulPlusVals(vec_first, vec_second);
}

By steps

1) you need to create your vector 2) hold this memory in heap 3) just copy the data

It is going to be much more faster