managed-unmanaged.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: managed, unmanaged pragmas	managed, unmanaged pragmas	08/29/2019	vc-pragma.unmanaged managed_CPP unmanaged_CPP vc-pragma.managed	managed pragma pragmas, unmanaged pragmas, managed unmanaged pragma	f072ddcc-e1ec-408a-8ce1-326ddb60e4a4

managed, unmanaged pragmas

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 will be 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 these pragmas:

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

• Add the pragma after #include statements. Don't use these pragmas before #include statements.

The compiler ignores the managed and unmanaged pragmas 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 managed
void func1() {
   System::Console::WriteLine("In managed function.");
}

// #pragma unmanaged
// push managed state on to stack and set unmanaged state
#pragma managed(push, off)

// func2 is unmanaged
void func2() {
   printf("In unmanaged function.\n");
}

// #pragma managed
#pragma managed(pop)

// main is managed
int main() {
   func1();
   func2();
}

In managed function.
In unmanaged function.

See also

Pragma directives and the __pragma keyword