# mpx

Directs the compiler to pass Intel® Memory Protection Extensions (Intel® MPX) bounds information along with any pointer-typed parameters.

## Syntax

Windows* OS: __declspec(mpx)

Linux* OS: __attribute__((mpx))

## Arguments

None |

## Description

When a function declared with this keyword is called, any pointer-typed parameters passed to the function will also have Intel® MPX bounds information passed. If the called function returns a pointer-typed object, the compiler will expect the function to return Intel® MPX bounds information along with the pointer object. Similarly, if this keyword is applied to a function definition, the function will expect the caller to pass Intel® MPX bounds information along with any pointer-type parameters. If the function returns a pointer-typed object, Intel® MPX bounds information will be returned with the object.

### Note

The usage of this attribute is intended for Windows code that contains hand-written Intel® MPX enhancements based on Intel® MPX inline assembly or calls to Intel® MPX intrinsics, and where the user does not wish to enable automatic Intel® MPX code generation.

Parent topic: Attributes