1// Copyright Daniel Wallin, David Abrahams 2005.
2// Copyright Cromwell D. Enage 2017.
3// Distributed under the Boost Software License, Version 1.0.
4// (See accompanying file LICENSE_1_0.txt or copy at
5// http://www.boost.org/LICENSE_1_0.txt)
6
7#ifndef BOOST_PARAMETER_CONFIG_050403_HPP
8#define BOOST_PARAMETER_CONFIG_050403_HPP
9
10#include <boost/config.hpp>
11#include <boost/config/workaround.hpp>
12
13// Allow projects to #define BOOST_PARAMETER_DISABLE_PERFECT_FORWARDING to
14// turn off perfect forwarding as necessary. Otherwise, also require correct
15// SFINAE support, needed explicitly by tagged_argument & keyword & cast;
16// correct function template ordering, needed by the code generation macros;
17// rvalue references, needed throughout; variadic templates, needed by
18// parameters; function template default arguments, needed by the code
19// generation macros; and the ability to handle multiple parameter packs,
20// needed by parameters. Older versions of GCC either don't have the latter
21// ability or cannot disambiguate between keyword's overloaded
22// operators. Older versions of Clang either fail to compile due to
23// differences in length between parameter packs 'Args' and 'args' or fail at
24// runtime due to segmentation faults.
25// -- Cromwell D. Enage
26#if !defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING) && \
27 !defined(BOOST_PARAMETER_DISABLE_PERFECT_FORWARDING) && \
28 !defined(BOOST_NO_SFINAE) && \
29 !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING) && \
30 !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && \
31 !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
32 !defined(BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS) && \
33 !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) && !( \
34 defined(BOOST_CLANG) && (1 == BOOST_CLANG) && ( \
35 (__clang_major__ < 3) || ( \
36 (3 == __clang_major__) && (__clang_minor__ < 2) \
37 ) \
38 ) \
39 ) && !BOOST_WORKAROUND(BOOST_GCC, < 40900)
40#define BOOST_PARAMETER_HAS_PERFECT_FORWARDING
41#endif
42
43#if defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING)
44#if !defined(BOOST_PARAMETER_CAN_USE_MP11) && \
45 !defined(BOOST_PARAMETER_DISABLE_MP11_USAGE) && \
46 !defined(BOOST_NO_CXX11_CONSTEXPR) && \
47 !defined(BOOST_NO_CXX11_DECLTYPE_N3276) && \
48 !defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) && \
49 !defined(BOOST_NO_CXX11_TEMPLATE_ALIASES) && \
50 !defined(BOOST_NO_CXX11_STATIC_ASSERT) && \
51 !defined(BOOST_NO_CXX11_HDR_TYPE_TRAITS) && \
52 !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST) && \
53 !defined(BOOST_NO_CXX11_HDR_TUPLE)
54// Boost.MP11 requires C++11. -- Cromwell D. Enage
55#define BOOST_PARAMETER_CAN_USE_MP11
56#endif
57#if !defined(BOOST_PARAMETER_MAX_ARITY)
58// Unlike the variadic MPL sequences provided by Boost.Fusion,
59// boost::mpl::vector has a size limit. -- Cromwell D. Enage
60#include <boost/mpl/limits/vector.hpp>
61#define BOOST_PARAMETER_MAX_ARITY BOOST_MPL_LIMIT_VECTOR_SIZE
62#endif
63#else // !defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING)
64#if !defined(BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY)
65#define BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY 0
66#endif
67#if !defined(BOOST_PARAMETER_COMPOSE_MAX_ARITY)
68#if BOOST_WORKAROUND(BOOST_MSVC, < 1800) || \
69 BOOST_WORKAROUND(BOOST_GCC, < 60000)
70// Some tests cause MSVC-11.0 and earlier to run out of heap space,
71// while some other tests cause GCC 5 and earlier to do the same,
72// if the value is set any higher. -- Cromwell D. Enage
73#define BOOST_PARAMETER_COMPOSE_MAX_ARITY 20
74#else
75#define BOOST_PARAMETER_COMPOSE_MAX_ARITY 64
76#endif
77#endif // BOOST_PARAMETER_COMPOSE_MAX_ARITY
78#if !defined(BOOST_PARAMETER_MAX_ARITY)
79#define BOOST_PARAMETER_MAX_ARITY 8
80#endif
81#endif // BOOST_PARAMETER_HAS_PERFECT_FORWARDING
82#endif // include guard
83
84

source code of include/boost/parameter/config.hpp