Chris@16: 
Chris@16: // Copyright (C) 2009-2012 Lorenzo Caminiti
Chris@16: // Distributed under the Boost Software License, Version 1.0
Chris@16: // (see accompanying file LICENSE_1_0.txt or a copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: // Home at http://www.boost.org/libs/local_function
Chris@16: 
Chris@16: #ifndef BOOST_LOCAL_FUNCTION_HPP_
Chris@16: #define BOOST_LOCAL_FUNCTION_HPP_
Chris@16: 
Chris@16: #ifndef DOXYGEN
Chris@16: 
Chris@16: #include <boost/local_function/aux_/macro/decl.hpp>
Chris@16: #include <boost/local_function/aux_/macro/name.hpp>
Chris@16: #include <boost/local_function/aux_/macro/typeof.hpp>
Chris@16: #include <boost/local_function/aux_/preprocessor/traits/decl.hpp>
Chris@16: #include <boost/local_function/detail/preprocessor/line_counter.hpp>
Chris@16: #include <boost/local_function/detail/preprocessor/void_list.hpp>
Chris@16: #include <boost/config.hpp>
Chris@16: 
Chris@16: // PUBLIC //
Chris@16: 
Chris@16: #ifdef BOOST_NO_CXX11_VARIADIC_MACROS
Chris@16: #   define BOOST_LOCAL_FUNCTION_ID(id, declarations) \
Chris@16:         BOOST_LOCAL_FUNCTION_AUX_DECL(id, 0 /* not within template */, \
Chris@16:                 BOOST_LOCAL_FUNCTION_AUX_PP_DECL_TRAITS( \
Chris@16:                         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST( \
Chris@16:                                 declarations)))
Chris@16: #   define BOOST_LOCAL_FUNCTION(declarations) \
Chris@16:         BOOST_LOCAL_FUNCTION_ID( \
Chris@16:                 BOOST_LOCAL_FUNCTION_DETAIL_PP_LINE_COUNTER, declarations)
Chris@16: #   define BOOST_LOCAL_FUNCTION_ID_TPL(id, declarations) \
Chris@16:         BOOST_LOCAL_FUNCTION_AUX_DECL(id, 1 /* within template */, \
Chris@16:                 BOOST_LOCAL_FUNCTION_AUX_PP_DECL_TRAITS( \
Chris@16:                         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST( \
Chris@16:                                 declarations)))
Chris@16: #   define BOOST_LOCAL_FUNCTION_TPL(declarations) \
Chris@16:         BOOST_LOCAL_FUNCTION_ID_TPL( \
Chris@16:                 BOOST_LOCAL_FUNCTION_DETAIL_PP_LINE_COUNTER, declarations)
Chris@16: #else // VARIADIC
Chris@16: #   define BOOST_LOCAL_FUNCTION_ID(id, ...) \
Chris@16:         BOOST_LOCAL_FUNCTION_AUX_DECL(id, 0 /* not within template */, \
Chris@16:                 BOOST_LOCAL_FUNCTION_AUX_PP_DECL_TRAITS( \
Chris@16:                         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST(__VA_ARGS__)))
Chris@16: #   define BOOST_LOCAL_FUNCTION(...) \
Chris@16:         BOOST_LOCAL_FUNCTION_ID( \
Chris@16:                 BOOST_LOCAL_FUNCTION_DETAIL_PP_LINE_COUNTER, __VA_ARGS__)
Chris@16: #   define BOOST_LOCAL_FUNCTION_ID_TPL(id, ...) \
Chris@16:         BOOST_LOCAL_FUNCTION_AUX_DECL(id, 1 /* within template */, \
Chris@16:                 BOOST_LOCAL_FUNCTION_AUX_PP_DECL_TRAITS( \
Chris@16:                         BOOST_LOCAL_FUNCTION_DETAIL_PP_VOID_LIST(__VA_ARGS__)))
Chris@16: #   define BOOST_LOCAL_FUNCTION_TPL(...) \
Chris@16:         BOOST_LOCAL_FUNCTION_ID_TPL( \
Chris@16:                 BOOST_LOCAL_FUNCTION_DETAIL_PP_LINE_COUNTER, __VA_ARGS__)
Chris@16: #endif // VARIADIC
Chris@16: 
Chris@16: #define BOOST_LOCAL_FUNCTION_NAME(qualified_name) \
Chris@16:     BOOST_LOCAL_FUNCTION_AUX_NAME(0 /* not within template */, qualified_name)
Chris@16: #define BOOST_LOCAL_FUNCTION_NAME_TPL(qualified_name) \
Chris@16:     BOOST_LOCAL_FUNCTION_AUX_NAME(1 /* within template */, qualified_name)
Chris@16: 
Chris@16: #define BOOST_LOCAL_FUNCTION_TYPEOF(bound_variable_name) \
Chris@16:     BOOST_LOCAL_FUNCTION_AUX_TYPEOF_TYPE(bound_variable_name)
Chris@16: 
Chris@16: // DOCUMENTATION //
Chris@16: 
Chris@16: #else // DOXYGEN
Chris@16: 
Chris@16: /** @file
Chris@16: @brief Local functions allow to program functions locally, within other
Chris@16: functions, and directly within the scope where they are needed.
Chris@16: */
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro is used to start a local function declaration.
Chris@16: 
Chris@16: This macro must be used within a declarative context, it must follow the local
Chris@16: function result type, it must be followed by the local function body code, and
Chris@16: then by the @RefMacro{BOOST_LOCAL_FUNCTION_NAME} macro (see the
Chris@16: @RefSect{tutorial, Tutorial} and @RefSect{advanced_topics, Advanced Topics}
Chris@16: sections):
Chris@16: @code
Chris@16: { // Some declarative context.
Chris@16:     ...
Chris@16:     result_type BOOST_LOCAL_FUNCTION(declarations) {
Chris@16:         ... // Body code.
Chris@16:     } BOOST_LOCAL_FUNCTION_NAME(qualified_name)
Chris@16:     ...
Chris@16: }
Chris@16: @endcode
Chris@16: 
Chris@16: As usual, exceptions specifications can be optionally programmed just after the
Chris@16: macro and before the body code block <c>{ ... }</c> (but the exception
Chris@16: specifications will only apply to the body code and not to the library code
Chris@16: automatically generated by the macro expansion, see the
Chris@16: @RefSect{advanced_topics, Advanced Topics} section).
Chris@16: 
Chris@16: Within templates, the special macros @RefMacro{BOOST_LOCAL_FUNCTION_TPL}
Chris@16: and @RefMacro{BOOST_LOCAL_FUNCTION_NAME_TPL} must be used.
Chris@16: 
Chris@16: @Params
Chris@16: @Param{declarations,
Chris@16: On compilers that support variadic macros\, the parameter declarations are
Chris@16: defined by the following grammar:
Chris@16: @code
Chris@16:     declarations:
Chris@16:             void | declaration_tuple | declaration_sequence
Chris@16:     declaration_tuple:
Chris@16:             declaration\, declaration\, ...
Chris@16:     declaration_sequence:
Chris@16:             (declaration) (declaration) ...
Chris@16:     declaration:
Chris@16:             bound_variable | parameter | default_value | result_type
Chris@16:     bound_variable:
Chris@16:             [const] bind [(variable_type)] [&] variable_name
Chris@16:     parameter:
Chris@16:             [auto | register] parameter_type parameter_name
Chris@16:     default_value:
Chris@16:             default parameter_default_value
Chris@16:     result_type:
Chris@16:             return function_result_type
Chris@16: @endcode
Chris@16: On compilers that do not support variadic macros\, <c>declaration_tuple</c>
Chris@16: cannot be used:
Chris@16: @code
Chris@16:     declarations:
Chris@16:             void | declaration_sequence
Chris@16: @endcode
Chris@16: 
Chris@16: (Lexical conventions: <c>token1 | token2</c> means either <c>token1</c> or
Chris@16: <c>token2</c>; <c>[token]</c> means either <c>token</c> or nothing;
Chris@16: <c>{expression}</c> means the token resulting from the expression.)
Chris@16: }
Chris@16: @EndParams
Chris@16:  
Chris@16: Note that on compilers that support variadic macros, commas can be used to
Chris@16: separate the declarations resembling more closely the usual C++ function
Chris@16: declaration syntax (this is the preferred syntax).
Chris@16: However, for portability, on all C++ compilers (with and without variadic
Chris@16: macros) the same library macros also accept parameter declarations specified as
Chris@16: a Boost.Preprocessor sequence separated by round parenthesis <c>()</c>.
Chris@16: 
Chris@16: When binding the object <c>this</c>, the special symbol <c>this_</c> needs to
Chris@16: be used instead of <c>this</c> as the name of the variable to bind and also
Chris@16: within the local function body to access the object.
Chris@16: (Mistakenly using <c>this</c> instead of <c>this_</c> might not always result in a compiler error and will in general result in undefined behaviour.)
Chris@16: 
Chris@16: The result type must either be specified just before the macro or within the
Chris@16: macro declarations prefixed by <c>return</c> (but not in both places).
Chris@16: 
Chris@16: Within the local function body it possible to access the result type using <c>result_type</c>, the type of the first parameter using <c>arg1_type</c>, the type of the second parameter using <c>arg2_type</c>, etc.
Chris@16: The bound variable types can be accessed using @RefMacro{BOOST_LOCAL_FUNCTION_TYPEOF}.
Chris@16: 
Chris@16: This macro cannot be portably expanded multiple times on the same line.
Chris@16: In these cases, use the @RefMacro{BOOST_LOCAL_FUNCTION_ID} macro instead.
Chris@16: 
Chris@16: The maximum number of local function parameters (excluding bound variables) is
Chris@16: specified by the configuration macro
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_ARITY_MAX}.
Chris@16: The maximum number of bound variables is specified by the configuration macro
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX}.
Chris@16: The configuration macro
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS} can be used to force
Chris@16: optimizations that reduce the local function call run-time overhead.
Chris@16: 
Chris@16: @Note Local functions are functors so they can be assigned to other functors
Chris@16: like <c>boost::function</c> (see Boost.Function).
Chris@16: 
Chris@16: @See @RefSect{tutorial, Tutorial} section,
Chris@16: @RefSect{advanced_topics, Advanced Topics} section,
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME}, @RefMacro{BOOST_LOCAL_FUNCTION_TPL},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME_TPL},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_TYPEOF}, @RefMacro{BOOST_LOCAL_FUNCTION_ID},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_ARITY_MAX},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_BIND_MAX},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION(declarations)
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro is used to start a local function declaration within
Chris@16: templates.
Chris@16: 
Chris@16: This macro must be used instead of @RefMacro{BOOST_LOCAL_FUNCTION} when
Chris@16: declaring a local function within a template.
Chris@16: A part from that, this macro has the exact same syntax a
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION} (see @RefMacro{BOOST_LOCAL_FUNCTION} for more
Chris@16: information):
Chris@16: @code
Chris@16: { // Some declarative context within a template.
Chris@16:     ...
Chris@16:     result_type BOOST_LOCAL_FUNCTION_TPL(declarations) {
Chris@16:         ... // Body code.
Chris@16:     } BOOST_LOCAL_FUNCTION_NAME_TPL(qualified_name)
Chris@16:     ...
Chris@16: }
Chris@16: @endcode
Chris@16: 
Chris@16: Note that @RefMacro{BOOST_LOCAL_FUNCTION_NAME_TPL} must be used with this
Chris@16: macro instead of @RefMacro{BOOST_LOCAL_FUNCTION_NAME}.
Chris@16: 
Chris@16: This macro cannot be portably expanded multiple times on the same line.
Chris@16: In these cases, use the @RefMacro{BOOST_LOCAL_FUNCTION_ID_TPL} macro instead.
Chris@16: 
Chris@16: @Note C++03 does not allow to use <c>typename</c> outside templates.
Chris@16: This library internally manipulates types, these operations require
Chris@16: <c>typename</c> but only within templates.
Chris@16: This macro is used to indicate to the library when the enclosing scope is a
Chris@16: template so the library can correctly use <c>typename</c>.
Chris@16: 
Chris@16: @See @RefSect{tutorial, Tutorial} section, @RefMacro{BOOST_LOCAL_FUNCTION},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_ID_TPL},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME_TPL}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION_TPL(declarations)
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro allows to declare multiple local functions on the same line.
Chris@16: 
Chris@16: This macro is equivalent to @RefMacro{BOOST_LOCAL_FUNCTION} but it can be
Chris@16: expanded multiple times on the same line if different identifiers <c>id</c> are
Chris@16: provided for each expansion (see the
Chris@16: @RefSect{advanced_topics, Advanced Topics} section).
Chris@16: 
Chris@16: @Params
Chris@16: @Param{id,
Chris@16: A unique identifier token which can be concatenated by the preprocessor
Chris@16: (<c>__LINE__</c>\, <c>local_function_number_1_on_line_123</c>\, etc).
Chris@16: }
Chris@16: @Param{declarations,
Chris@16: Same as the <c>declarations</c> parameter of the
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION} macro.
Chris@16: }
Chris@16: @EndParams
Chris@16: 
Chris@16: The @RefMacro{BOOST_LOCAL_FUNCTION_NAME} macro should be used to end each one
Chris@16: of the multiple local function declarations as usual (and it will specify a
Chris@16: unique name for each local function).
Chris@16: 
Chris@16: Within templates, the special macros @RefMacro{BOOST_LOCAL_FUNCTION_ID_TPL}
Chris@16: must be used.
Chris@16: 
Chris@16: @Note This macro can be useful when the local function macros are expanded
Chris@16: within user-defined macros (because macros all expand on the same line).
Chris@16: On some compilers (e.g., MSVC which supports the non-standard
Chris@16: <c>__COUNTER__</c> macro) it might not be necessary to use this macro but
Chris@16: the use of this macro when expanding multiple local function macros on the same
Chris@16: line is always necessary to ensure portability (this is because this library
Chris@16: can only portably use <c>__LINE__</c> to internally generate unique
Chris@16: identifiers).
Chris@16: 
Chris@16: @See @RefSect{advanced_topics, Advanced Topics} section,
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION}, @RefMacro{BOOST_LOCAL_FUNCTION_NAME},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_ID_TPL}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION_ID(id, declarations)
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro allows to declare multiple local functions on the same line
Chris@16: within templates.
Chris@16: 
Chris@16: This macro must be used instead of @RefMacro{BOOST_LOCAL_FUNCTION_TPL} when
Chris@16: declaring multiple local functions on the same line within a template.
Chris@16: A part from that, this macro has the exact same syntax as
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_TPL} (see @RefMacro{BOOST_LOCAL_FUNCTION_TPL}
Chris@16: for more information).
Chris@16: 
Chris@16: @Params
Chris@16: @Param{id,
Chris@16: A unique identifier token which can be concatenated by the preprocessor
Chris@16: (<c>__LINE__</c>\, <c>local_function_number_1_on_line_123</c>\, etc).
Chris@16: }
Chris@16: @Param{declarations,
Chris@16: Same as the <c>declarations</c> parameter of the
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_TPL} macro.
Chris@16: }
Chris@16: @EndParams
Chris@16: 
Chris@16: The @RefMacro{BOOST_LOCAL_FUNCTION_NAME} macro should be used to end each one
Chris@16: of the multiple local function declarations as usual (and it will specify a
Chris@16: unique name for each local function).
Chris@16: 
Chris@16: Outside template, the macro @RefMacro{BOOST_LOCAL_FUNCTION_ID} should be used
Chris@16: to declare multiple local functions on the same line.
Chris@16: 
Chris@16: @Note This macro can be useful when the local function macros are expanded
Chris@16: within user-defined macros (because macros all expand on the same line).
Chris@16: On some compilers (e.g., MSVC which supports the non-standard
Chris@16: <c>__COUNTER__</c> macro) it might not be necessary to use this macro but
Chris@16: the use of this macro when expanding multiple local function macros on the same
Chris@16: line is always necessary to ensure portability (this is because this library
Chris@16: can only portably use <c>__LINE__</c> to internally generate unique
Chris@16: identifiers).
Chris@16: 
Chris@16: @See @RefSect{advanced_topics, Advanced Topics} section,
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_TPL}, @RefMacro{BOOST_LOCAL_FUNCTION_NAME},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_ID}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION_ID_TPL(id, declarations)
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro is used to end a local function declaration specifying its
Chris@16: name.
Chris@16: 
Chris@16: This macro must follow the local function body code block <c>{ ... }</c>:
Chris@16: @code
Chris@16: { // Some declarative context.
Chris@16:     ...
Chris@16:     result_type BOOST_LOCAL_FUNCTION(declarations) {
Chris@16:         ... // Body code.
Chris@16:     } BOOST_LOCAL_FUNCTION_NAME(qualified_name)
Chris@16:     ...
Chris@16: }
Chris@16: @endcode
Chris@16: 
Chris@16: Within templates, the special macros @RefMacro{BOOST_LOCAL_FUNCTION_TPL} and
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME_TPL} must be used.
Chris@16: 
Chris@16: @Params
Chris@16: @Param{qualified_name,
Chris@16: The name of the local function optionally qualified as follow:
Chris@16: @code
Chris@16:     name:
Chris@16:             [inline] [recursive] local_function_name
Chris@16: @endcode
Chris@16: (Lexical conventions: <c>token1 | token2</c> means either <c>token1</c> or
Chris@16: <c>token2</c>; <c>[token]</c> means either <c>token</c> or nothing;
Chris@16: <c>{expression}</c> means the token resulting from the expression.)
Chris@16: }
Chris@16: @EndParams
Chris@16: 
Chris@16: The local function name can be qualified by prefixing it with the keyword
Chris@16: <c>inline</c> (see the @RefSect{advanced_topics, Advanced Topics} section):
Chris@16: @code
Chris@16:     BOOST_LOCAL_FUNCTION_NAME(inline local_function_name)
Chris@16: @endcode
Chris@16: This increases the chances that the compiler will be able to inline the local
Chris@16: function calls (thus reducing run-time).
Chris@16: However, inline local functions cannot be passed as template parameters (e.g., to <c>std::for_each</c>) or assigned to other functors (e.g., to
Chris@16: <c>boost::function</c>).
Chris@16: That is true on C++03 compilers but inline local functions can instead be
Chris@16: passed as template parameters on C++11 compilers.
Chris@16: On C++11 compilers, there is no need to declare a local function lined because
Chris@16: this library will automatically use C++11 specific features to inline the local
Chris@16: function while always allowing to pass it as a template parameter.
Chris@16: This optimization is automatically enabled when the Boost.Config macro
Chris@16: <c>BOOST_NO_CXX11_LOCAL_CLASS_TEMPLATE_PARAMETERS</c> is not defined but it also be
Chris@16: forced using @RefMacro{BOOST_LOCAL_FUNCTION_CONFIG_LOCALS_AS_TPARAMS}.
Chris@16: 
Chris@16: The local function name can also be qualified by prefixing it with the
Chris@16: "keyword" <c>recursive</c> (see the
Chris@16: @RefSect{advanced_topics, Advanced Topics} section):
Chris@16: @code
Chris@16:     BOOST_LOCAL_FUNCTION_NAME(recursive local_function_name)
Chris@16: @endcode
Chris@16: This allows the local function to recursively call itself from its body (as
Chris@16: usual in C++).
Chris@16: However, recursive local functions should only be called within their
Chris@16: declaration scope (otherwise the result is undefined behaviour).
Chris@16: Finally, compilers have not been observed to be able to inline recursive local
Chris@16: function calls, not even when the recursive local function is also declared
Chris@16: inline:
Chris@16: @code
Chris@16:     BOOST_LOCAL_FUNCTION(inline recursive local_function_name)
Chris@16: @endcode
Chris@16: 
Chris@16: @Note The local function name cannot be the name of an operator
Chris@16: <c>operator...</c> and it cannot be the same name of another local function
Chris@16: declared within the same enclosing scope (but <c>boost::overloaded_function</c>
Chris@16: can be used to overload local functions, see
Chris@16: Boost.Functional/OverloadedFunction and the
Chris@16: @RefSect{advanced_topics, Advanced Topics} section).
Chris@16: 
Chris@16: @See @RefSect{tutorial, Tutorial} section,
Chris@16: @RefSect{advanced_topics, Advanced Topics} section,
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION},
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME_TPL}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION_NAME(qualified_name)
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro is used to end a local function declaration specifying its
Chris@16: name within templates.
Chris@16: 
Chris@16: This macro must be used instead of @RefMacro{BOOST_LOCAL_FUNCTION_NAME} when
Chris@16: declaring a local function within a template.
Chris@16: A part from that, this macro has the exact same syntax a
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME} (see @RefMacro{BOOST_LOCAL_FUNCTION_NAME}
Chris@16: for more information):
Chris@16: @code
Chris@16: { // Some declarative context within a template.
Chris@16:     ...
Chris@16:     result_type BOOST_LOCAL_FUNCTION_TPL(declarations) {
Chris@16:         ... // Body code.
Chris@16:     } BOOST_LOCAL_FUNCTION_NAME_TPL(qualified_name)
Chris@16:     ...
Chris@16: }
Chris@16: @endcode
Chris@16: 
Chris@16: Note that @RefMacro{BOOST_LOCAL_FUNCTION_TPL} must be used with this macro
Chris@16: instead of @RefMacro{BOOST_LOCAL_FUNCTION}.
Chris@16: 
Chris@16: @Note C++03 does not allow to use <c>typename</c> outside templates.
Chris@16: This library internally manipulates types, these operations require
Chris@16: <c>typename</c> but only within templates.
Chris@16: This macro is used to indicate to the library when the enclosing scope is a
Chris@16: template so the library can correctly use <c>typename</c>.
Chris@16: 
Chris@16: @See @RefSect{tutorial, Tutorial} section,
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION_NAME}, @RefMacro{BOOST_LOCAL_FUNCTION_TPL}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION_NAME_TPL(name)
Chris@16: 
Chris@16: /**
Chris@16: @brief This macro expands to the type of the specified bound variable.
Chris@16: 
Chris@16: This macro can be used within the local functions body to refer to the bound
Chris@16: variable types so to declare local variables, check concepts (using
Chris@16: Boost.ConceptCheck), etc (see the @RefSect{advanced_topics, Advanced Topics}
Chris@16: section).
Chris@16: This way the local function can be programmed entirely without explicitly
Chris@16: specifying the bound variable types thus facilitating maintenance (e.g., if
Chris@16: the type of a bound variable changes in the enclosing scope, the local function
Chris@16: code does not have to change).
Chris@16: 
Chris@16: @Params
Chris@16: @Param{bound_variable_name,
Chris@16: The name of one of the local function's bound variables.
Chris@16: }
Chris@16: @EndParams
Chris@16: 
Chris@16: The type returned by the macro is fully qualified in that it contains the extra
Chris@16: constant and reference qualifiers when the specified variable is bound by
Chris@16: constant and by reference.
Chris@16: For example, if a variable named <c>t</c> of type <c>T</c> is:
Chris@16: @li Bound by value using <c>bind t</c> then
Chris@16: <c>BOOST_LOCAL_FUNCTION_TYPEOF(t)</c> is <c>T</c>.
Chris@16: @li Bound by constant value using <c>const bind t</c> then
Chris@16: <c>BOOST_LOCAL_FUNCTION_TYPEOF(t)</c> is <c>const T</c>.
Chris@16: @li Bound by reference using <c>bind& t</c> then
Chris@16: <c>BOOST_LOCAL_FUNCTION_TYPEOF(t)</c> is <c>T&</c>.
Chris@16: @li Bound by constant reference using <c>const bind& t</c> then
Chris@16: <c>BOOST_LOCAL_FUNCTION_TYPEOF(t)</c> is <c>const T&</c>.
Chris@16: 
Chris@16: This macro must be prefixed by <c>typename</c> when used within templates.
Chris@16: 
Chris@16: @Note It is best to use this macro instead of Boost.Typeof so to reduce the
Chris@16: number of times Boost.Typeof is used to deduce types (see the
Chris@16: @RefSect{advanced_topics, Advanced Topics} section).
Chris@16: 
Chris@16: @See @RefSect{advanced_topics, Advanced Topics} section,
Chris@16: @RefMacro{BOOST_LOCAL_FUNCTION}.
Chris@16: */
Chris@16: #define BOOST_LOCAL_FUNCTION_TYPEOF(bound_variable_name)
Chris@16: 
Chris@16: #endif // DOXYGEN
Chris@16: 
Chris@16: #endif // #include guard
Chris@16: