boost/local_function/config.hpp

0001
0002 // Copyright (C) 2009-2012 Lorenzo Caminiti
0003 // Distributed under the Boost Software License, Version 1.0
0004 // (see accompanying file LICENSE_1_0.txt or a copy at
0005 // http://www.boost.org/LICENSE_1_0.txt)
0006 // Home at http://www.boost.org/libs/local_function
0007
0008 #ifndef BOOST_LOCAL_FUNCTION_CONFIG_HPP_
0009 #define BOOST_LOCAL_FUNCTION_CONFIG_HPP_
0010
0011 #ifndef DOXYGEN
0012
0013 #include <boost/config.hpp>
0014
0015 #ifndef BOOST_LOCAL_FUNCTION_CONFIG_FUNCTION_ARITY_MAX
0016 #   define BOOST_LOCAL_FUNCTION_CONFIG_FUNCTION_ARITY_MAX 5
0017 #endif
0018
0019 #ifndef BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX
0020 #   define BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX 10
0021 #endif
0022
0023 #ifndef BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS
0024 #   ifdef BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS
0025 #       define BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS 0
0026 #   else
0027 #       define BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS 1
0028 #   endif
0029 #elif BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS // If true, force it to 1.
0030 #   undef BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS
0031 #   define BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS 1
0032 #endif
0033
0034 #else // DOXYGEN
0035
0036 /** @file
0037 @brief Configuration macros allow to change the behaviour of this library at
0038 compile-time.
0039 */
0040
0041 /**
0042 @brief Maximum number of parameters supported by local functions.
0043
0044 If programmers leave this configuration macro undefined, its default
0045 value is <c>5</c> (increasing this number might increase compilation time).
0046 When defined by programmers, this macro must be a non-negative integer number.
0047
0048 @Note This macro specifies the maximum number of local function parameters
0049 excluding bound variables (which are instead specified by
0050 @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX}).
0051
0052 @See @RefSect{tutorial, Tutorial} section,
0053 @RefSect{getting_started, Getting Started} section,
0054 @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX}.
0055 */
0056 #define BOOST_LOCAL_FUNCTION_CONFIG_ARITY_MAX
0057
0058 /**
0059 @brief Maximum number of bound variables supported by local functions.
0060
0061 If programmers leave this configuration macro undefined, its default
0062 value is <c>10</c> (increasing this number might increase compilation time).
0063 When defined by programmers, this macro must be a non-negative integer number.
0064
0065 @Note This macro specifies the maximum number of bound variables excluding
0066 local function parameters (which are instead specified by
0067 @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_ARITY_MAX}).
0068
0069 @See @RefSect{tutorial, Tutorial} section,
0070 @RefSect{getting_started, Getting Started} section,
0071 @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_ARITY_MAX}.
0072 */
0073 #define BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX
0074
0075 /**
0076 @brief Specify when local functions can be passed as template parameters
0077 without introducing any run-time overhead.
0078
0079 If this macro is defined to <c>1</c>, this library will assume that the
0080 compiler allows to pass local classes as template parameters:
0081 @code
0082     template<typename T> void f(void) {}
0083
0084     int main(void) {
0085         struct local_class {};
0086         f<local_class>();
0087         return 0;
0088     }
0089 @endcode
0090 This is the case for C++11 compilers and some C++03 compilers (e.g., MSVC), but
0091 it is not the case in general for most C++03 compilers (including GCC).
0092 This will allow the library to pass local functions as template parameters
0093 without introducing any run-time overhead (specifically without preventing the
0094 compiler from optimizing local function calls by inlining their assembly code).
0095
0096 If this macro is defined to <c>0</c> instead, this library will introduce
0097 a run-time overhead associated to resolving a function pointer call in order to
0098 still allow to pass the local functions as template parameters.
0099
0100 It is recommended to leave this macro undefined.
0101 In this case, the library will automatically define this macro to <c>0</c> if
0102 the Boost.Config macro <c>BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS</c> is
0103 defined for the specific compiler, and to <c>1</c> otherwise.
0104
0105 @See @RefSect{getting_started, Getting Started} section,
0106 @RefSect{advanced_topics, Advanced Topics} section,
0107 @RefMacro{BOOST_LOCAL_FUNCTION_NAME}.
0108 */
0109 #define BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS
0110
0111 #endif // DOXYGEN
0112
0113 #endif // #include guard
0114