// (C) Copyright Edward Diener 2011-2015
// Use, modification and distribution are subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt).
#if !defined(BOOST_VMD_TEST_DOC_EXAMPLE_SWITCH_HPP)
#define BOOST_VMD_TEST_DOC_EXAMPLE_SWITCH_HPP
//[ example_switch
#include <boost/vmd/detail/setup.hpp>
#if BOOST_PP_VARIADICS
#include <boost/preprocessor/cat.hpp>
#include <boost/preprocessor/arithmetic/inc.hpp>
#include <boost/preprocessor/comparison/equal.hpp>
#include <boost/preprocessor/control/expr_iif.hpp>
#include <boost/preprocessor/control/iif.hpp>
#include <boost/preprocessor/control/while.hpp>
#include <boost/preprocessor/tuple/elem.hpp>
#include <boost/preprocessor/tuple/enum.hpp>
#include <boost/preprocessor/facilities/expand.hpp>
#include <boost/preprocessor/tuple/replace.hpp>
#include <boost/preprocessor/tuple/size.hpp>
#include <boost/preprocessor/variadic/to_tuple.hpp>
#include <boost/preprocessor/variadic/size.hpp>
#include <boost/vmd/equal.hpp>
#include <boost/vmd/identity.hpp>
#include <boost/vmd/is_empty.hpp>
/*
State index into state values
*/
#define BOOST_VMD_SWITCH_STATE_ELEM_INDEX 2
#define BOOST_VMD_SWITCH_STATE_ELEM_DEFAULT 4
#define BOOST_VMD_SWITCH_STATE_ELEM_RESULT 5
/*
Retrieve the state value, never changes
*/
#define BOOST_VMD_SWITCH_STATE_GET_VALUE(state) \
BOOST_PP_TUPLE_ELEM(0,state) \
/**/
/*
Retrieve the state tuple of values, never changes
*/
#define BOOST_VMD_SWITCH_STATE_GET_CHOICES(state) \
BOOST_PP_TUPLE_ELEM(1,state) \
/**/
/*
Retrieve the state index
*/
#define BOOST_VMD_SWITCH_STATE_GET_INDEX(state) \
BOOST_PP_TUPLE_ELEM(2,state) \
/**/
/*
Retrieve the state tuple of values size, never changes
*/
#define BOOST_VMD_SWITCH_STATE_GET_SIZE(state) \
BOOST_PP_TUPLE_ELEM(3,state) \
/**/
/*
Retrieve the state default tuple
*/
#define BOOST_VMD_SWITCH_STATE_GET_DEFAULT(state) \
BOOST_PP_TUPLE_ELEM(4,state) \
/**/
/*
Retrieve the state result tuple
*/
#define BOOST_VMD_SWITCH_STATE_GET_RESULT(state) \
BOOST_PP_TUPLE_ELEM(5,state) \
/**/
/*
Retrieve the current value tuple
*/
#define BOOST_VMD_SWITCH_STATE_GET_CURRENT_CHOICE(state) \
BOOST_PP_TUPLE_ELEM \
( \
BOOST_VMD_SWITCH_STATE_GET_INDEX(state), \
BOOST_VMD_SWITCH_STATE_GET_CHOICES(state) \
) \
/**/
/*
Expands to the state
value = value to compare against
tuple = choices as a tuple of values
size = size of tuple of values
None of these ever change in the WHILE state
*/
#define BOOST_VMD_SWITCH_STATE_EXPAND(value,tuple,size) \
(value,tuple,0,size,(0,),(,)) \
/**/
/*
Expands to the WHILE state
The state to our WHILE consists of a tuple of elements:
1: value to compare against
2: tuple of values. Each value is a value/macro pair or if the default just a macro
3: index into the values
4: tuple for default macro. 0 means no default macro, 1 means default macro and then second value is the default macro.
5: tuple of result matched. Emptiness means no result yet specified, 0 means no match, 1 means match and second value is the matching macro.
*/
#define BOOST_VMD_SWITCH_STATE(value,...) \
BOOST_VMD_SWITCH_STATE_EXPAND \
( \
value, \
BOOST_PP_VARIADIC_TO_TUPLE(__VA_ARGS__), \
BOOST_PP_VARIADIC_SIZE(__VA_ARGS__) \
) \
/**/
/*
Sets the state upon a successful match.
macro = is the matching macro found
*/
#define BOOST_VMD_SWITCH_OP_SUCCESS(d,state,macro) \
BOOST_PP_TUPLE_REPLACE_D \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_ELEM_RESULT, \
(1,macro) \
) \
/**/
/*
Sets the state upon final failure to find a match.
def = default tuple macro, ignored
*/
#define BOOST_VMD_SWITCH_OP_FAILURE(d,state,def) \
BOOST_PP_TUPLE_REPLACE_D \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_ELEM_RESULT, \
(0,) \
) \
/**/
/*
Increments the state index into the tuple values
*/
#define BOOST_VMD_SWITCH_OP_UPDATE_INDEX(d,state) \
BOOST_PP_TUPLE_REPLACE_D \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_ELEM_INDEX, \
BOOST_PP_INC(BOOST_VMD_SWITCH_STATE_GET_INDEX(state)) \
) \
/**/
/*
Choose our current value's macro as our successful match
tuple = current tuple to test
*/
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_VALUE_MATCH(d,state,tuple) \
BOOST_VMD_SWITCH_OP_SUCCESS(d,state,BOOST_PP_TUPLE_ELEM(1,tuple)) \
/**/
/*
Update our state index
tuple = current tuple to test, ignored
*/
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_VALUE_UPDATE_INDEX(d,state,tuple) \
BOOST_VMD_SWITCH_OP_UPDATE_INDEX(d,state) \
/**/
/*
Test our current value against our value to compare against
tuple = current tuple to test
*/
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_VALUE(d,state,tuple) \
BOOST_PP_IIF \
( \
BOOST_VMD_EQUAL_D \
( \
d, \
BOOST_VMD_SWITCH_STATE_GET_VALUE(state), \
BOOST_PP_TUPLE_ELEM(0,tuple) \
), \
BOOST_VMD_SWITCH_OP_TEST_CURRENT_VALUE_MATCH, \
BOOST_VMD_SWITCH_OP_TEST_CURRENT_VALUE_UPDATE_INDEX \
) \
(d,state,tuple) \
/**/
/*
Set our default macro and update the index in our WHILE state
tuple = current tuple to test
*/
#if BOOST_VMD_MSVC
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_CREATE_DEFAULT_NN(number,name) \
(number,name) \
/**/
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_CREATE_DEFAULT(d,state,tuple) \
BOOST_VMD_SWITCH_OP_UPDATE_INDEX \
( \
d, \
BOOST_PP_TUPLE_REPLACE_D \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_ELEM_DEFAULT, \
BOOST_VMD_SWITCH_OP_TEST_CURRENT_CREATE_DEFAULT_NN(1,BOOST_PP_TUPLE_ENUM(tuple)) \
) \
) \
/**/
#else
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_CREATE_DEFAULT(d,state,tuple) \
BOOST_VMD_SWITCH_OP_UPDATE_INDEX \
( \
d, \
BOOST_PP_TUPLE_REPLACE_D \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_ELEM_DEFAULT, \
(1,BOOST_PP_TUPLE_ENUM(tuple)) \
) \
) \
/**/
#endif
/*
If our current value is a default macro, just set the default macro,
else test our current value.
tuple = current tuple to test
*/
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT_TUPLE(d,state,tuple) \
BOOST_PP_IIF \
( \
BOOST_PP_EQUAL_D \
( \
d, \
BOOST_PP_TUPLE_SIZE(tuple), \
1 \
), \
BOOST_VMD_SWITCH_OP_TEST_CURRENT_CREATE_DEFAULT, \
BOOST_VMD_SWITCH_OP_TEST_CURRENT_VALUE \
) \
(d,state,tuple) \
/**/
/*
Test the current value in our tuple of values
*/
#define BOOST_VMD_SWITCH_OP_TEST_CURRENT(d,state) \
BOOST_VMD_SWITCH_OP_TEST_CURRENT_TUPLE \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_GET_CURRENT_CHOICE(state) \
) \
/**/
/*
Choose the default macro as our successful match
def = default tuple consisting of just the default macro name
*/
#define BOOST_VMD_SWITCH_OP_DEFAULT_RET_CHOSEN(d,state,def) \
BOOST_VMD_SWITCH_OP_SUCCESS \
( \
d, \
state, \
BOOST_PP_TUPLE_ELEM(1,def) \
) \
/**/
/*
If the default macro exists, choose it else indicate no macro was found
def = default tuple consisting of just the default macro name
*/
#define BOOST_VMD_SWITCH_OP_DEFAULT_RET(d,state,def) \
BOOST_PP_IIF \
( \
BOOST_PP_TUPLE_ELEM(0,def), \
BOOST_VMD_SWITCH_OP_DEFAULT_RET_CHOSEN, \
BOOST_VMD_SWITCH_OP_FAILURE \
) \
(d,state,def) \
/**/
/*
Try to choose the default macro if it exists
*/
#define BOOST_VMD_SWITCH_OP_DEFAULT(d,state) \
BOOST_VMD_SWITCH_OP_DEFAULT_RET \
( \
d, \
state, \
BOOST_VMD_SWITCH_STATE_GET_DEFAULT(state) \
) \
/**/
/*
WHILE loop operation
Check for the next value match or try to choose the default if all matches have been checked
*/
#define BOOST_VMD_SWITCH_OP(d,state) \
BOOST_PP_IIF \
( \
BOOST_PP_EQUAL_D \
( \
d, \
BOOST_VMD_SWITCH_STATE_GET_INDEX(state), \
BOOST_VMD_SWITCH_STATE_GET_SIZE(state) \
), \
BOOST_VMD_SWITCH_OP_DEFAULT, \
BOOST_VMD_SWITCH_OP_TEST_CURRENT \
) \
(d,state) \
/**/
/*
WHILE loop predicate
Continue the WHILE loop if a result has not yet been specified
*/
#define BOOST_VMD_SWITCH_PRED(d,state) \
BOOST_VMD_IS_EMPTY \
( \
BOOST_PP_TUPLE_ELEM \
( \
0, \
BOOST_VMD_SWITCH_STATE_GET_RESULT(state) \
) \
) \
/**/
/*
Invokes the function-like macro
macro = function-like macro name
tparams = tuple of macro parameters
*/
#define BOOST_VMD_SWITCH_PROCESS_INVOKE_MACRO(macro,tparams) \
BOOST_PP_EXPAND(macro tparams) \
/**/
/*
Processes our WHILE loop result
callp = tuple of parameters for the called macro
result = tuple. The first tuple element is 0
if no macro has been found or 1 if a macro
has been found. If 1 the second element is
the name of a function-like macro
*/
#define BOOST_VMD_SWITCH_PROCESS(callp,result) \
BOOST_PP_EXPR_IIF \
( \
BOOST_PP_TUPLE_ELEM(0,result), \
BOOST_VMD_SWITCH_PROCESS_INVOKE_MACRO \
( \
BOOST_PP_TUPLE_ELEM(1,result), \
callp \
) \
) \
/**/
/*
Use BOOST_VMD_SWITCH_IDENTITY to pass a fixed value instead
of a function-like macro as the second element of
any tuple of the variadic parameters, or as the default
value, to BOOST_VMD_SWITCH.
*/
#if BOOST_VMD_MSVC
#define BOOST_VMD_SWITCH_IDENTITY(item) BOOST_PP_CAT(BOOST_VMD_IDENTITY(item),)
#else
#define BOOST_VMD_SWITCH_IDENTITY BOOST_VMD_IDENTITY
#endif
/*
Switch macro
Parameters are:
value = value to compare against. May be any VMD data value.
callp = tuple of parameters for the called macro
variadic parameters = each parameter must be a tuple.
Each tuple consists of a two-element tuple. The first element is
a value, which may be any VMD data value, and the second element
is the name of a function-like macro to be called if the value
is equal to the value to compare against. For a default value
the tuple is a single-element tuple which contains the name of
a function-like macro to be called if no other value matches.
*/
#define BOOST_VMD_SWITCH(value,callp,...) \
BOOST_VMD_SWITCH_PROCESS \
( \
callp, \
BOOST_VMD_SWITCH_STATE_GET_RESULT \
( \
BOOST_PP_WHILE \
( \
BOOST_VMD_SWITCH_PRED, \
BOOST_VMD_SWITCH_OP, \
BOOST_VMD_SWITCH_STATE(value,__VA_ARGS__) \
) \
) \
) \
/**/
#endif /* BOOST_PP_VARIADICS */
//]
#endif /* BOOST_VMD_TEST_DOC_EXAMPLE_SWITCH_HPP */
