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libs/scope_exit/test/same_line.cpp


// Copyright (C) 2006-2009, 2012 Alexander Nasonov
// Copyright (C) 2012 Lorenzo Caminiti
// Distributed under the Boost Software License, Version 1.0
// (see accompanying file LICENSE_1_0.txt or a copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Home at http://www.boost.org/libs/scope_exit

#include <boost/config.hpp>
#ifdef BOOST_NO_VARIADIC_MACROS
#   error "variadic macros required"
#else

#include <boost/scope_exit.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/detail/lightweight_test.hpp>

//[same_line
#define SCOPE_EXIT_INC_DEC(variable, offset) \
    BOOST_SCOPE_EXIT_ID(BOOST_PP_CAT(inc, __LINE__), /* unique ID */ \
            &variable, offset) { \
        variable += offset; \
    } BOOST_SCOPE_EXIT_END_ID(BOOST_PP_CAT(inc, __LINE__)) \
    \
    BOOST_SCOPE_EXIT_ID(BOOST_PP_CAT(dec, __LINE__), \
            &variable, offset) { \
        variable -= offset; \
    } BOOST_SCOPE_EXIT_END_ID(BOOST_PP_CAT(dec, __LINE__))

#define SCOPE_EXIT_INC_DEC_TPL(variable, offset) \
    BOOST_SCOPE_EXIT_ID_TPL(BOOST_PP_CAT(inc, __LINE__), \
            &variable, offset) { \
        variable += offset; \
    } BOOST_SCOPE_EXIT_END_ID(BOOST_PP_CAT(inc, __LINE__)) \
    \
    BOOST_SCOPE_EXIT_ID_TPL(BOOST_PP_CAT(dec, __LINE__), \
            &variable, offset) { \
        variable -= offset; \
    } BOOST_SCOPE_EXIT_END_ID(BOOST_PP_CAT(dec, __LINE__))

#define SCOPE_EXIT_ALL_INC_DEC(variable, offset) \
    BOOST_SCOPE_EXIT_ALL_ID(BOOST_PP_CAT(inc, __LINE__), \
            =, &variable) { \
        variable += offset; \
    }; \
    BOOST_SCOPE_EXIT_ALL_ID(BOOST_PP_CAT(dec, __LINE__), \
            =, &variable) { \
        variable -= offset; \
    };

template<typename T>
void f(T& x, T& delta) {
    SCOPE_EXIT_INC_DEC_TPL(x, delta) // Multiple scope exits on same line.
    BOOST_TEST(x == 0);
}

int main(void) {
    int x = 0, delta = 10;

    {
        SCOPE_EXIT_INC_DEC(x, delta) // Multiple scope exits on same line.
    }
    BOOST_TEST(x == 0);

    f(x, delta);

#ifndef BOOST_NO_LAMBDAS
    {
        SCOPE_EXIT_ALL_INC_DEC(x, delta) // Multiple scope exits on same line.
    }
    BOOST_TEST(x == 0);
#endif // LAMBDAS
    
    return boost::report_errors();
}
//]

#endif // variadic macros