编译需要开启C++14支持
// fun.h
#include<boost/preprocessor.hpp>
#define SIZE(...) BOOST_PP_TUPLE_SIZE((__VA_ARGS__))
#define _CAT(a, b) a##b
#define CAT(a, b) _CAT(a, b)
#define _STRING(a) #a
#define STRING(a) _STRING(a)
#define OP_HEAD(d, state, x) \
(BOOST_PP_SUB(BOOST_PP_TUPLE_ELEM(2, 0, state), 1), \
BOOST_PP_LIST_CONS(typename CAT(_, BOOST_PP_TUPLE_ELEM(2, 0, state)), BOOST_PP_TUPLE_ELEM(2, 1, state)))
#define OP_BODY(d, state, x) \
(BOOST_PP_SUB(BOOST_PP_TUPLE_ELEM(2, 0, state), 1), \
BOOST_PP_LIST_CONS(CAT(_, BOOST_PP_TUPLE_ELEM(2, 0, state)) x, BOOST_PP_TUPLE_ELEM(2, 1, state)))
#define FUN_HEAD(...) \
template<BOOST_PP_REMOVE_PARENS( \
BOOST_PP_LIST_TO_TUPLE( \
BOOST_PP_TUPLE_ELEM(2, 1, \
BOOST_PP_LIST_FOLD_RIGHT(OP_HEAD, (SIZE(__VA_ARGS__), BOOST_PP_LIST_NIL), \
BOOST_PP_TUPLE_TO_LIST((__VA_ARGS__))))))>
#define FUN_BODY(...) \
BOOST_PP_LIST_TO_TUPLE( \
BOOST_PP_TUPLE_ELEM(2, 1, \
BOOST_PP_LIST_FOLD_RIGHT(OP_BODY, (SIZE(__VA_ARGS__), BOOST_PP_LIST_NIL), \
BOOST_PP_TUPLE_TO_LIST((__VA_ARGS__)))))
#define FUN(f, ...) \
FUN_HEAD(__VA_ARGS__) auto f FUN_BODY(__VA_ARGS__)
测试
#include <iostream>
#include "fun.h"
namespace test {
FUN(plus, a, b) {
return a + b;
}
FUN(push, &a, b) {
a.push_back(b);
}
}
int main(int argc, char **argv) {
// test plus
std::cout << test::plus(1, 2) << std::endl;
// test push
std::vector<int> v {1, 2, 3};
test::push(v, 4);
for (auto & i : v) std::cout << i << ' ';
std::cout << std::endl;
return 0;
}
结果
3
1 2 3 4
