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Merge various result_of changes.

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- [42234] Reduce header dependencies, from Shunsuke Sogame. Fixes #1535
 - [45256] result_of implementation that makes use of C++0x decltype, from Daniel Walker. Fixes #862.
 - [48620] Fix result_of to work with const-qualified function pointers. Fixes #1310
 - [60052] Remove use of deprecated config macro in result_of.



[SVN r60289]
This commit is contained in:
Daniel James 2010-03-07 12:08:00 +00:00
parent a47dce770c
commit b4dee80e61
4 changed files with 194 additions and 16 deletions
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54
include/boost/utility/detail/result_of_iterate.hpp
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@ -10,6 +10,47 @@
# error Boost result_of - do not include this file!
#endif
#if !defined(BOOST_NO_DECLTYPE)
// As of N2588, C++0x result_of only supports function call
// expressions of the form f(x). This precludes support for member
// function pointers, which are invoked with expressions of the form
// o->*f(x). This implementation supports both.
template<typename F BOOST_PP_COMMA_IF(BOOST_PP_ITERATION())
BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),typename T)>
struct result_of<F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T))>
: mpl::if_<
mpl::or_< is_pointer<F>, is_member_function_pointer<F> >
, detail::result_of_impl<
typename remove_cv<F>::type,
typename remove_cv<F>::type(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T)), false
>
, detail::result_of_decltype_impl<
F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T))
>
>::type
{};
namespace detail {
# define BOOST_RESULT_OF_STATIC_MEMBERS(z, n, _) \
static T ## n t ## n; \
/**/
template<typename F BOOST_PP_COMMA_IF(BOOST_PP_ITERATION())
BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),typename T)>
class result_of_decltype_impl<F(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),T))>
{
static F f;
BOOST_PP_REPEAT(BOOST_PP_ITERATION(), BOOST_RESULT_OF_STATIC_MEMBERS, _)
public:
typedef decltype(f(BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),t))) type;
};
} // namespace detail
#else // defined(BOOST_HAS_DECLTYPE)
// CWPro8 requires an argument in a function type specialization
#if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3002)) && BOOST_PP_ITERATION() == 0
# define BOOST_RESULT_OF_ARGS void
@ -21,11 +62,22 @@
template<typename F BOOST_PP_COMMA_IF(BOOST_PP_ITERATION())
BOOST_PP_ENUM_PARAMS(BOOST_PP_ITERATION(),typename T)>
struct result_of<F(BOOST_RESULT_OF_ARGS)>
: boost::detail::result_of_impl<F, F(BOOST_RESULT_OF_ARGS), (boost::detail::has_result_type<F>::value)> {};
: mpl::if_<
mpl::or_< is_pointer<F>, is_member_function_pointer<F> >
, boost::detail::result_of_impl<
typename remove_cv<F>::type,
typename remove_cv<F>::type(BOOST_RESULT_OF_ARGS),
(boost::detail::has_result_type<F>::value)>
, boost::detail::result_of_impl<
F,
F(BOOST_RESULT_OF_ARGS),
(boost::detail::has_result_type<F>::value)> >::type { };
#endif
#undef BOOST_RESULT_OF_ARGS
#endif // defined(BOOST_HAS_DECLTYPE)
#if BOOST_PP_ITERATION() >= 1
namespace detail {

17
include/boost/utility/result_of.hpp
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@ -10,13 +10,18 @@
#define BOOST_RESULT_OF_HPP
#include <boost/config.hpp>
#include <boost/type_traits/ice.hpp>
#include <boost/type.hpp>
#include <boost/preprocessor.hpp>
#include <boost/preprocessor/iteration/iterate.hpp>
#include <boost/preprocessor/punctuation/comma_if.hpp>
#include <boost/preprocessor/repetition/enum_params.hpp>
#include <boost/preprocessor/repetition/enum_shifted_params.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/mpl/has_xxx.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/or.hpp>
#include <boost/type_traits/is_pointer.hpp>
#include <boost/type_traits/is_member_function_pointer.hpp>
#include <boost/type_traits/remove_cv.hpp>
#ifndef BOOST_RESULT_OF_NUM_ARGS
# define BOOST_RESULT_OF_NUM_ARGS 10
@ -32,6 +37,7 @@ namespace detail {
BOOST_MPL_HAS_XXX_TRAIT_DEF(result_type)
template<typename F, typename FArgs, bool HasResultType> struct result_of_impl;
template<typename F> struct result_of_decltype_impl;
template<typename F>
struct result_of_void_impl
@ -51,6 +57,11 @@ struct result_of_void_impl<R (&)(void)>
typedef R type;
};
// Determine the return type of a function pointer or pointer to member.
template<typename F, typename FArgs>
struct result_of_pointer
: result_of_impl<typename remove_cv<F>::type, FArgs, false> { };
template<typename F, typename FArgs>
struct result_of_impl<F, FArgs, true>
{

131
test/result_of_test.cpp
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@ -11,35 +11,101 @@
#include <boost/static_assert.hpp>
#include <boost/type_traits/is_same.hpp>
struct int_result_type { typedef int result_type; };
struct int_result_type
{
typedef int result_type;
result_type operator()(float);
};
struct int_result_of
{
template<typename F> struct result { typedef int type; };
result<int_result_of(double)>::type operator()(double);
result<const int_result_of(double)>::type operator()(double) const;
result<int_result_of()>::type operator()();
result<volatile int_result_of()>::type operator()() volatile;
};
struct int_result_type_and_float_result_of
struct int_result_type_and_float_result_of_and_char_return
{
typedef int result_type;
template<typename F> struct result { typedef float type; };
char operator()(char);
};
template<typename T>
struct int_result_type_template { typedef int result_type; };
struct int_result_type_template
{
typedef int result_type;
result_type operator()(float);
};
template<typename T>
struct int_result_of_template
{
template<typename F> struct result;
template<typename This, typename That> struct result<This(That)> { typedef int type; };
typename result<int_result_of_template<T>(double)>::type operator()(double);
typename result<const int_result_of_template<T>(double)>::type operator()(double) const;
typename result<int_result_of_template<T>(double)>::type operator()();
typename result<volatile int_result_of_template<T>(double)>::type operator()() volatile;
};
template<typename T>
struct int_result_type_and_float_result_of_template
struct int_result_type_and_float_result_of_and_char_return_template
{
typedef int result_type;
template<typename F> struct result;
template<typename This, typename That> struct result<This(That)> { typedef float type; };
char operator()(char);
};
struct result_of_member_function_template
{
template<typename F> struct result;
template<typename This, typename That> struct result<This(That)> { typedef That type; };
template<class T> typename result<result_of_member_function_template(T)>::type operator()(T);
template<typename This, typename That> struct result<const This(That)> { typedef const That type; };
template<class T> typename result<const result_of_member_function_template(T)>::type operator()(T) const;
template<typename This, typename That> struct result<volatile This(That)> { typedef volatile That type; };
template<class T> typename result<volatile result_of_member_function_template(T)>::type operator()(T) volatile;
template<typename This, typename That> struct result<const volatile This(That)> { typedef const volatile That type; };
template<class T> typename result<const volatile result_of_member_function_template(T)>::type operator()(T) const volatile;
template<typename This, typename That> struct result<This(That &, That)> { typedef That & type; };
template<class T> typename result<result_of_member_function_template(T &, T)>::type operator()(T &, T);
template<typename This, typename That> struct result<This(That const &, That)> { typedef That const & type; };
template<class T> typename result<result_of_member_function_template(T const &, T)>::type operator()(T const &, T);
template<typename This, typename That> struct result<This(That volatile &, That)> { typedef That volatile & type; };
template<class T> typename result<result_of_member_function_template(T volatile &, T)>::type operator()(T volatile &, T);
template<typename This, typename That> struct result<This(That const volatile &, That)> { typedef That const volatile & type; };
template<class T> typename result<result_of_member_function_template(T const volatile &, T)>::type operator()(T const volatile &, T);
};
struct no_result_type_or_result_of
{
int operator()(double);
short operator()(double) const;
unsigned int operator()();
unsigned short operator()() volatile;
const unsigned short operator()() const volatile;
};
template<typename T>
struct no_result_type_or_result_of_template
{
int operator()(double);
short operator()(double) const;
unsigned int operator()();
unsigned short operator()() volatile;
const unsigned short operator()() const volatile;
};
struct X {};
@ -60,16 +126,37 @@ int main()
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type(float)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of(double)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const int_result_of(double)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of(char)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_template<void>(float)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of_template<void>(double)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of_template<void>(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const int_result_of_template<void>(double)>::type, int>::value));
// Prior to decltype, result_of could not deduce the return type
// nullary function objects unless they exposed a result_type.
#if defined(BOOST_HAS_DECLTYPE)
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of(void)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of(void)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of_template<void>(void)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of_template<void>(void)>::type, int>::value));
#else
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_of_template<void>(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile int_result_of_template<void>(void)>::type, void>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of_template<void>(char)>::type, int>::value));
#endif
// Prior to decltype, result_of ignored a nested result<> if
// result_type was defined. After decltype, result_of deduces the
// actual return type of the function object, ignoring both
// result<> and result_type.
#if defined(BOOST_HAS_DECLTYPE)
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of_and_char_return(char)>::type, char>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of_and_char_return_template<void>(char)>::type, char>::value));
#else
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of_and_char_return(char)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<int_result_type_and_float_result_of_and_char_return_template<void>(char)>::type, int>::value));
#endif
BOOST_STATIC_ASSERT((is_same<result_of<func_ptr(char, float)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<func_ref(char, float)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<func_ptr_0()>::type, int>::value));
@ -81,5 +168,31 @@ int main()
BOOST_STATIC_ASSERT((is_same<result_of<mem_func_ptr_0(X)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<func_ptr(void)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<result_of_member_function_template(double)>::type, double>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const result_of_member_function_template(double)>::type, const double>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile result_of_member_function_template(double)>::type, volatile double>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const volatile result_of_member_function_template(double)>::type, const volatile double>::value));
BOOST_STATIC_ASSERT((is_same<result_of<result_of_member_function_template(int &, int)>::type, int &>::value));
BOOST_STATIC_ASSERT((is_same<result_of<result_of_member_function_template(int const &, int)>::type, int const &>::value));
BOOST_STATIC_ASSERT((is_same<result_of<result_of_member_function_template(int volatile &, int)>::type, int volatile &>::value));
BOOST_STATIC_ASSERT((is_same<result_of<result_of_member_function_template(int const volatile &, int)>::type, int const volatile &>::value));
typedef int (*pf_t)(int);
BOOST_STATIC_ASSERT((is_same<result_of<pf_t(int)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<pf_t const(int)>::type,int>::value));
#if defined(BOOST_HAS_DECLTYPE)
BOOST_STATIC_ASSERT((is_same<result_of<no_result_type_or_result_of(double)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<no_result_type_or_result_of(void)>::type, unsigned int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const no_result_type_or_result_of(double)>::type, short>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile no_result_type_or_result_of(void)>::type, unsigned short>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const volatile no_result_type_or_result_of(void)>::type, const unsigned short>::value));
BOOST_STATIC_ASSERT((is_same<result_of<no_result_type_or_result_of_template<void>(double)>::type, int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<no_result_type_or_result_of_template<void>(void)>::type, unsigned int>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const no_result_type_or_result_of_template<void>(double)>::type, short>::value));
BOOST_STATIC_ASSERT((is_same<result_of<volatile no_result_type_or_result_of_template<void>(void)>::type, unsigned short>::value));
BOOST_STATIC_ASSERT((is_same<result_of<const volatile no_result_type_or_result_of_template<void>(void)>::type, const unsigned short>::value));
#endif
return 0;
}

8
utility.htm
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@ -154,11 +154,13 @@ void f() {
...,t<em>N</em>)</code>. The implementation permits
the type <code>F</code> to be a function pointer,
function reference, member function pointer, or class
type. When <code>F</code> is a class type with a
member type <code>result_type</code>,
type.</p> <p>If your compiler does not support
<code>decltype</code>, then when <code>F</code> is a
class type with a member type <code>result_type</code>,
<code>result_of&lt;F(T1, T2, ...,
T<em>N</em>)&gt;</code> is
<code>F::result_type</code>. Otherwise,
<code>F::result_type</code>. When <code>F</code>
does not contain <code>result_type</code>,
<code>result_of&lt;F(T1, T2, ...,
T<em>N</em>)&gt;</code> is <code>F::result&lt;F(T1,
T2, ..., T<em>N</em>)&gt;::type</code> when