C++ is used in as diverse fields as high-level GUI through the lowest level real-time applications. In time-critical sections of C++ code, you can ensure enhanced responsiveness by combining inline assembly instructions. The asm keyword designates a block of native assembly code:

 // A flight control app with high level UI and time-critical sections implemented in assembly string city ( "CPH" );  gis.display(city); //display a flight map on the screenasm          // inline asm block; Wintel assembly code used here{	push ecx	//_additional assembly code}gis.alert( "ten more minutes to landing" );

Keep in mind that combining inline assembly instructions in your C++ code limits its portability.