Inline Functions

Microsoft Specific

The __inline keyword tells the compiler to substitute the code within the function definition for every instance of a function call. However, substitution occurs only at the compiler's discretion. For example, the compiler does not inline a function if its address is taken or if it is too large to inline.

For a function to be considered as a candidate for inlining, it must use the new-style function definition.

Use this form to specify an inline function:

__inline typeopt function-definition

The use of inline functions generates faster code and can sometimes generate smaller code than the equivalent function call generates for the following reasons:

  • It saves the time required to execute function calls.

  • Small inline functions, perhaps three lines or less, create less code than the equivalent function call because the compiler doesn't generate code to handle arguments and a return value.

  • Functions generated inline are subject to code optimizations not available to normal functions because the compiler does not perform interprocedural optimizations.

Functions using __inline should not be confused with inline assembler code. See Inline Assembler for more information.

END Microsoft Specific

See also

inline, __inline, __forceinline