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Add mp_cond

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This commit is contained in:
Peter Dimov
2017-10-14 02:53:38 +03:00
parent 602147bf31
commit 30fcc21d8b
4 changed files with 112 additions and 0 deletions
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25
include/boost/mp11/utility.hpp
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@@ -107,6 +107,31 @@ template<bool C, class T, template<class...> class F, class... U> using mp_eval_
template<class C, class T, template<class...> class F, class... U> using mp_eval_if = typename detail::mp_eval_if_c_impl<static_cast<bool>(C::value), T, F, U...>::type;
template<class C, class T, class Q, class... U> using mp_eval_if_q = typename detail::mp_eval_if_c_impl<static_cast<bool>(C::value), T, Q::template fn, U...>::type;
// mp_cond
// so elegant; so doesn't work
// template<class C, class T, class... E> using mp_cond = mp_eval_if<C, T, mp_cond, E...>;
namespace detail
{
template<class C, class T, class... E> struct mp_cond_impl;
} // namespace detail
template<class C, class T, class... E> using mp_cond = typename detail::mp_cond_impl<C, T, E...>::type;
namespace detail
{
template<class C, class T, class... E> using mp_cond_ = mp_eval_if<C, T, mp_cond, E...>;
template<class C, class T, class... E> struct mp_cond_impl: mp_defer<mp_cond_, C, T, E...>
{
};
} // namespace detail
// mp_quote
template<template<class...> class F> struct mp_quote
{

2
test/Jamfile
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@@ -90,6 +90,8 @@ run mp_quote.cpp ;
run mp_invoke.cpp ;
run mp_invoke_sf.cpp ;
run mp_quote_trait.cpp ;
run mp_cond.cpp ;
run mp_cond_sf.cpp ;
# integer_sequence
run integer_sequence.cpp ;

42
test/mp_cond.cpp Normal file
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@@ -0,0 +1,42 @@
// Copyright 2017 Peter Dimov.
//
// Distributed under 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
#include <boost/mp11/utility.hpp>
#include <boost/mp11/integral.hpp>
#include <boost/core/lightweight_test_trait.hpp>
#include <type_traits>
int main()
{
using boost::mp11::mp_cond;
using boost::mp11::mp_true;
using boost::mp11::mp_false;
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_true, char[]>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_true, char[], void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_true, char[], void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_true, char[], void, void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_true, char[]>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_true, char[], void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_true, char[], void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_true, char[], void, void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_true, char[]>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_true, char[], void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_true, char[], void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_true, char[], void, void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_false, double, mp_true, char[]>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_false, double, mp_true, char[], void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_false, double, mp_true, char[], void, void>, char[]>));
BOOST_TEST_TRAIT_TRUE((std::is_same<mp_cond<mp_false, int, mp_false, float, mp_false, double, mp_true, char[], void, void, void>, char[]>));
return boost::report_errors();
}

43
test/mp_cond_sf.cpp Normal file
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@@ -0,0 +1,43 @@
// Copyright 2017 Peter Dimov.
//
// Distributed under 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
#include <boost/mp11/utility.hpp>
#include <boost/mp11/integral.hpp>
#include <boost/core/lightweight_test_trait.hpp>
#include <type_traits>
int main()
{
using boost::mp11::mp_cond;
using boost::mp11::mp_true;
using boost::mp11::mp_false;
using boost::mp11::mp_valid;
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_true>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false>));
BOOST_TEST_TRAIT_TRUE((mp_valid<mp_cond, mp_true, void>));
BOOST_TEST_TRAIT_TRUE((mp_valid<mp_cond, mp_true, void, void>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false, void>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false, void, void>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false, void, mp_true>));
BOOST_TEST_TRAIT_TRUE((mp_valid<mp_cond, mp_false, void, mp_true, void>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false, void, mp_false>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false, void, mp_false, void>));
BOOST_TEST_TRAIT_FALSE((mp_valid<mp_cond, mp_false, void, mp_false, void, mp_true>));
BOOST_TEST_TRAIT_TRUE((mp_valid<mp_cond, mp_false, void, mp_false, void, mp_true, void>));
return boost::report_errors();
}