dispatch.h File Reference

Function dispatch for variable arguments. More...

Go to the source code of this file.

Macros
#define	GET(n, t)   CONCAT(GET, n) t
	Accessor macro for simulated tuples. More...
#define	GET0(x0, ...)   x0
#define	GET1(x0, x1, ...)   x1
#define	GET2(x0, x1, x2, ...)   x2
#define	GET3(x0, x1, x2, x3, ...)   x3
#define	GET4(x0, x1, x2, x3, x4, ...)   x4
#define	GET5(x0, x1, x2, x3, x4, x5, ...)   x5
#define	GET6(x0, x1, x2, x3, x4, x5, x6, ...)   x6
#define	GET7(x0, x1, x2, x3, x4, x5, x6, x7, ...)   x7
#define	GET8(x0, x1, x2, x3, x4, x5, x6, x7, x8, ...)   x8
#define	GET20(x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15, x16, x17, x18, x19, x20, ...)   x20
#define	ARG_COUNT(...)   GET20(_X, ##__VA_ARGS__, _19, _18, _17, _16, _15, _14, _13, _12, _11, _10, _9, _8, _7, _6, _5, _4, _3, _2, _1, _0)
	Return the number of arguments.
#define	DISPATCH(m, ...)   CONCAT(m, ARG_COUNT(__VA_ARGS__))(__VA_ARGS__)
	macro to allow handling optional macro arguments DISPATCH(MACRO_NAME, ...) calls MACRO_NAME_N(...) where N is the number of arguments other than MACRO_NAME. More...
#define	FORARG_2(name, x0)
#define	FORARG_3(name, x0, x1)
#define	FORARG_4(name, x0, x1, x2)
#define	FORARG_5(name, x0, x1, x2, x3)
#define	FORARG_6(name, x0, x1, x2, x3, x4)
#define	FORARG_7(name, x0, x1, x2, x3, x4, x5)
#define	FORARG_8(name, x0, x1, x2, x3, x4, x5, x6)
#define	FORARG_9(name, x0, x1, x2, x3, x4, x5, x6, x7)
#define	FORARG_10(name, x0, x1, x2, x3, x4, x5, x6, x7, x8)
#define	FORARG(name, ...)   DISPATCH(FORARG, name, __VA_ARGS__)
	Create a macro that iterates over its arguments. More...
#define	DUMMY_args   (x, x, x, x, x, x, x, x, x)
#define	DROP_pre
#define	DROP_first(s, x)
#define	DROP_middle(x)   ,x
#define	DROP_last(x)   ,x
#define	DROP_only(s, x)
#define	DROP_post
#define	DROP_args   DUMMY_args
#define	DROP(...)   FORARG(DROP, __VA_ARGS__)

Detailed Description

Function dispatch for variable arguments.

Macro Definition Documentation

DISPATCH

#define DISPATCH	(		m,
			...
	)		CONCAT(m, ARG_COUNT(__VA_ARGS__))(__VA_ARGS__)

macro to allow handling optional macro arguments DISPATCH(MACRO_NAME, ...) calls MACRO_NAME_N(...) where N is the number of arguments other than MACRO_NAME.

The typical use is: #define MACRO_NAME(...) DISPATCH(MACRO_NAME, VA_ARGS) to define an overloaded macro that takes a variable number of arguments

#define TEST_0() printf("TEST_0()\n")
#define TEST_1(x0) printf("TEST_1(" x0 ")\n")
#define TEST_2(x0, x1) printf("TEST_2(" x0 ", " x1 ")\n")

TEST(macro_dispatch) {
  DISPATCH(TEST);
  DISPATCH(TEST, "1");
  DISPATCH(TEST, "1", "2");
  return 0;
}

FORARG

#define FORARG	(		name,
			...
	)		DISPATCH(FORARG, name, __VA_ARGS__)

Create a macro that iterates over its arguments.

FORARG is a flexible iteration macro that can expand its arguments into repeated actions.

FORARG(NAME, ...) where #define NAME_pre expanded before FORARG(NAME, ...) #define NAME_first(s, x) s is selected from NAME_args based on the number of arguments x is the first argument #define NAME_middle(x) x is an argument that is neither first nor last #define NAME_last(x) x is the last argument #define NAME_only(x) x is the only argument #define NAME_post expanded after FORARG(NAME, ...) #define NAME_args (x0, x1, ..., xN) used in NAME_first for s

FORARG_10

#define FORARG_10	(		name,
			x0,
			x1,
			x2,
			x3,
			x4,
			x5,
			x6,
			x7,
			x8
	)

Value:

CONCAT(name, _pre)                                            \
  CONCAT(name, _first)(GET(8, CONCAT(name, _args)), x0)         \
  CONCAT(name, _middle)(x1)                                     \
  CONCAT(name, _middle)(x2)                                     \
  CONCAT(name, _middle)(x3)                                     \
  CONCAT(name, _middle)(x4)                                     \
  CONCAT(name, _middle)(x5)                                     \
  CONCAT(name, _middle)(x6)                                     \
  CONCAT(name, _middle)(x7)                                     \
  CONCAT(name, _last)(x8)                                       \
  CONCAT(name, _post)

FORARG_2

#define FORARG_2	(		name,
			x0
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _only)(GET(0, CONCAT(name, _args)), x0)  \
  CONCAT(name, _post)

FORARG_3

#define FORARG_3	(		name,
			x0,
			x1
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _first)(GET(1, CONCAT(name, _args)), x0) \
  CONCAT(name, _last)(x1)                               \
  CONCAT(name, _post)

FORARG_4

#define FORARG_4	(		name,
			x0,
			x1,
			x2
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _first)(GET(2, CONCAT(name, _args)), x0) \
  CONCAT(name, _middle)(x1)                             \
  CONCAT(name, _last)(x2)                               \
  CONCAT(name, _post)

FORARG_5

#define FORARG_5	(		name,
			x0,
			x1,
			x2,
			x3
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _first)(GET(3, CONCAT(name, _args)), x0) \
  CONCAT(name, _middle)(x1)                             \
  CONCAT(name, _middle)(x2)                             \
  CONCAT(name, _last)(x3)                               \
  CONCAT(name, _post)

FORARG_6

#define FORARG_6	(		name,
			x0,
			x1,
			x2,
			x3,
			x4
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _first)(GET(4, CONCAT(name, _args)), x0) \
  CONCAT(name, _middle)(x1)                             \
  CONCAT(name, _middle)(x2)                             \
  CONCAT(name, _middle)(x3)                             \
  CONCAT(name, _last)(x4)                               \
  CONCAT(name, _post)

FORARG_7

#define FORARG_7	(		name,
			x0,
			x1,
			x2,
			x3,
			x4,
			x5
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _first)(GET(5, CONCAT(name, _args)), x0) \
  CONCAT(name, _middle)(x1)                             \
  CONCAT(name, _middle)(x2)                             \
  CONCAT(name, _middle)(x3)                             \
  CONCAT(name, _middle)(x4)                             \
  CONCAT(name, _last)(x5)                               \
  CONCAT(name, _post)

FORARG_8

#define FORARG_8	(		name,
			x0,
			x1,
			x2,
			x3,
			x4,
			x5,
			x6
	)

Value:

CONCAT(name, _pre)                                    \
  CONCAT(name, _first)(GET(6, CONCAT(name, _args)), x0) \
  CONCAT(name, _middle)(x1)                             \
  CONCAT(name, _middle)(x2)                             \
  CONCAT(name, _middle)(x3)                             \
  CONCAT(name, _middle)(x4)                             \
  CONCAT(name, _middle)(x5)                             \
  CONCAT(name, _last)(x6)                               \
  CONCAT(name, _post)

FORARG_9

#define FORARG_9	(		name,
			x0,
			x1,
			x2,
			x3,
			x4,
			x5,
			x6,
			x7
	)

Value:

CONCAT(name, _pre)                                            \
  CONCAT(name, _first)(GET(7, CONCAT(name, _args)), x0)         \
  CONCAT(name, _middle)(x1)                                     \
  CONCAT(name, _middle)(x2)                                     \
  CONCAT(name, _middle)(x3)                                     \
  CONCAT(name, _middle)(x4)                                     \
  CONCAT(name, _middle)(x5)                                     \
  CONCAT(name, _middle)(x6)                                     \
  CONCAT(name, _last)(x7)                                       \
  CONCAT(name, _post)

GET

#define GET	(		n,
			t
	)		CONCAT(GET, n) t

Accessor macro for simulated tuples.

GET(N, (x0, x1, ..., xN)) returns xN