Managed Extensions for C++

Managed Extensions for C++ or just Managed C++ is a now deprecated Microsoft set of deviations from C++, including grammatical and syntactic extensions, keywords and attributes, to bring the C++ syntax and language to the .NET Framework. These extensions allowed C++ code to be targeted to the Common Language Runtime (CLR) in the form of managed code as well as continue to interoperate with native code. Managed C++ was not a complete standalone, or full-fledged programming language.

In 2004, the Managed C++ extensions were significantly revised to clarify and simplify syntax and expand functionality to include managed generics. These new extensions were designated C++/CLI and included in Microsoft Visual Studio 2005. The term Managed C++ and the extensions it refers to are thus deprecated and superseded by the new extensions. The information provided in this article relates to the older extensions.

"Managed" refers to managed code that it is run in, or managed by, the .NET virtual machine that functions as a sandbox for enhanced security in the form of more runtime checks, such as buffer overrun checks. Additionally, applications written in Managed C++ compile to CIL — Common Intermediate Language — and not directly to native CPU instructions like regular C++ applications do.

Managed C++ code could inter-operate with any other language also targeted for the CLR such as C# and Visual Basic .NET as well as make use of features provided by the CLR such as garbage collection. This means Managed C++ occupies a unique position in the gallery of .NET languages. It is the only language that can communicate directly with .NET languages (such as C#, VB.NET) and native C++. The other .NET languages can only communicate with C++ code via PInvoke or COM. But since Managed C++ can communicate directly in both managed and standard C++ contexts, it is often used as a "bridge".

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