Atmel CAVR-4 Manual De Usuario

CAVR-4

Part 2. Compiler reference

Inline assembler can be used for inserting assembler instructions in the generated 
function. 

The syntax for inline assembler is:

asm("MOVW R4,R7");

In strict ISO/ANSI mode, the use of inline assembler is disabled.

For more details about inline assembler, see Mixing C and assembler, page 93.

C++ style comments are accepted. A C++ style comment starts with the character 
sequence 

//

 and continues to the end of the line. For example:

// The length of the bar, in centimeters.

int length;

For information about alignment, see Alignment, page 137, and __ALIGNOF__(), page 
229.

To create compound literals you can use the following syntax:

/* Create a pointer to an anonymous array */

int *p = (int []) {1,2,3};

/* Create a pointer to an anonymous structX */

structX *px = &(structX) {5,6,7};

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A compound literal can be modified unless it is declared 

const

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Compound literals are not supported in Embedded C++.

C++ includes a feature named anonymous unions. The AVR IAR C/C++ Compiler allow 
a similar feature for both structs and unions.

An anonymous structure type (that is, one without a name) defines an unnamed object 
(and not a type) whose members are promoted to the surrounding scope. External 
anonymous structure types are allowed.