How to: Convert from a STL/CLR Container to a .NET Collection

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at How to: Convert from a STL/CLR Container to a .NET Collection.

This topic shows how to convert STL/CLR containers to their equivalent .NET collections. As an example, we show how to convert a STL/CLR vector to a .NET ICollection<T> and how to convert a STL/CLR map to a .NET IDictionary<TKey, TValue>, but the procedure is similar for all collections and containers.

To create a collection from a container

1. Use one of the following methods:

   • To convert part of a container, call the make_collection function, and pass the begin iterator and end iterator of the STL/CLR container to be copied into the .NET collection. This template function takes an STL/CLR iterator as a template argument. The first example demonstrates this method.

   • To convert an entire container, cast the container to an appropriate .NET collection interface or interface collection. The second example demonstrates this method.

Example

In this example, we create a STL/CLR vector and add 5 elements to it. Then, we create a .NET collection by calling the make_collection function. Finally, we display the contents of the newly created collection.

// cliext_convert_vector_to_icollection.cpp  
// compile with: /clr  
  
#include <cliext/adapter>  
#include <cliext/vector>  
  
using namespace cliext;  
using namespace System;  
using namespace System::Collections::Generic;  
  
int main(array<System::String ^> ^args)  
{  
    cliext::vector<int> primeNumbersCont;  
    primeNumbersCont.push_back(2);  
    primeNumbersCont.push_back(3);  
    primeNumbersCont.push_back(5);  
    primeNumbersCont.push_back(7);  
    primeNumbersCont.push_back(11);  
  
    System::Collections::Generic::ICollection<int> ^iColl =  
        make_collection<cliext::vector<int>::iterator>(  
            primeNumbersCont.begin() + 1,  
            primeNumbersCont.end() - 1);  
  
    Console::WriteLine("The contents of the System::Collections::Generic::ICollection are:");  
    for each (int i in iColl)  
    {  
        Console::WriteLine(i);  
    }  
}  

The contents of the System::Collections::Generic::ICollection are:  
3  
5  
7  

Example

In this example, we create a STL/CLR map and add 5 elements to it. Then, we create a .NET IDictionary<TKey, TValue> and assign the map directly to it. Finally, we display the contents of the newly created collection.

// cliext_convert_map_to_idictionary.cpp  
// compile with: /clr  
  
#include <cliext/adapter>  
#include <cliext/map>  
  
using namespace cliext;  
using namespace System;  
using namespace System::Collections::Generic;  
  
int main(array<System::String ^> ^args)  
{  
    cliext::map<float, int> ^aMap = gcnew cliext::map<float, int>;  
    aMap->insert(cliext::make_pair<float, int>(42.0, 42));  
    aMap->insert(cliext::make_pair<float, int>(13.0, 13));  
    aMap->insert(cliext::make_pair<float, int>(74.0, 74));  
    aMap->insert(cliext::make_pair<float, int>(22.0, 22));  
    aMap->insert(cliext::make_pair<float, int>(0.0, 0));  
  
    System::Collections::Generic::IDictionary<float, int> ^iDict = aMap;  
  
    Console::WriteLine("The contents of the IDictionary are:");  
    for each (KeyValuePair<float, int> ^kvp in iDict)  
    {  
        Console::WriteLine("Key: {0:F} Value: {1}", kvp->Key, kvp->Value);  
    }  
}  

The contents of the IDictionary are:  
Key: 0.00 Value: 0  
Key: 13.00 Value: 13  
Key: 22.00 Value: 22  
Key: 42.00 Value: 42  
Key: 74.00 Value: 74  

See Also

STL/CLR Library Reference
How to: Convert from a .NET Collection to a STL/CLR Container
range_adapter (STL/CLR)