function-specifier := inline

The inline function specifier can be used with any function or member function to hint to the compiler that the function should be expanded inline at the point of call. The compiler is free to ignore the hint. The compiler is also free to expand functions inline that are declared without the inline specifier, so long as this does not affect the semantics of the program.

An inline function must be defined in the same source file where it is used, before it is used. An inline function can be defined in more than one file (unlike other functions); the definition in every file must be the same.

A member function that is defined within a class definition is implicitly declared inline.

Example

struct point {
  inline point(int x, int y) : x_(x), y_(y) {} // Redundant
  inline point(  );
private:
  int x_, y_;
};
inline point::point(  ) : x_(0), y_(0) {}

See Also

class, declaration, function, type, Chapter 5