managed-unmanaged.md

description	title	ms.date	f1_keywords	helpviewer_keywords	no-loc
Learn more about managed and unmanaged pragma directives in Microsoft C++	managed and unmanaged pragma	01/22/2021	vc-pragma.unmanaged managed_CPP unmanaged_CPP vc-pragma.managed	managed pragma pragma, unmanaged pragma, managed unmanaged pragma	pragma

managed and unmanaged pragma

Enable function-level control to compile functions as managed or unmanaged.

Syntax

#pragma managed
#pragma unmanaged
#pragma managed( [ push, ] { on | off } )
#pragma managed(pop)

Remarks

The /clr compiler option provides module-level control for compiling functions either as managed or unmanaged.

An unmanaged function is compiled for the native platform. Execution of that portion of the program will be passed to the native platform by the common language runtime.

Functions are compiled as managed by default when /clr is used.

When applying a managed or unmanaged pragma:

• Add the pragma preceding a function, but not within a function body.

• Add the pragma after #include statements. Don't use it before any #include statements.

The compiler ignores the managed and unmanaged pragma if /clr isn't used in the compilation.

When a template function is instantiated, the pragma state when the template is defined determines if it's managed or unmanaged.

For more information, see Initialization of mixed assemblies.

Example

// pragma_directives_managed_unmanaged.cpp// compile with: /clr #include<stdio.h>// func1 is managedvoidfunc1() { System::Console::WriteLine("In managed function."); } // #pragma unmanaged// push managed state on to stack and set unmanaged state #pragma managed(push, off) // func2 is unmanagedvoidfunc2() { printf("In unmanaged function.\n"); } // #pragma managed #pragma managed(pop) // main is managedintmain() { func1(); func2(); }

In managed function. In unmanaged function. 

See also

Pragma directives and the __pragma and _Pragma keywords