Erfordert der Copy-Konstruktor von std :: function, dass die Argumenttypen des Vorlagentyps vollständige Typen sind?
Gegeben:
#include <functional>
class world_building_gun;
class tile_bounding_box;
typedef std::function<void (world_building_gun, tile_bounding_box)> worldgen_function_t;
void foo() {
worldgen_function_t v;
worldgen_function_t w(v);
}
Sollte dies kompilieren? Meine Compiler sagen:
Ja: GCC / stdlibc ++ (auch boost :: function ist in GCC und Clang ja)
Nein: Clang / libc ++ (http://libcxx.llvm.org/ , Clang 3.0, libc ++ SVN (Stand heute)
(Wenn "nein" die richtige Antwort ist, korrigiere ich meinen realen Code, um vollständige Typen in weitere Header einzufügen, oder verwende die boost :: -Funktion.)
BEARBEITEN: Hier ist die Clang-Fehlermeldung:
In file included from foo.cpp:2:
In file included from /usr/include/c++/v1/functional:462:
/usr/include/c++/v1/type_traits:2766:19: error: invalid appli
static_assert(sizeof(_Tp) > 0, "Type must be complete.");
^~~~~~~~~~~
/usr/include/c++/v1/type_traits:2752:15: note: in instantiation of template class 'std::__1::__check_complete<world_buildin
: private __check_complete<_Hp>,
^
/usr/include/c++/v1/type_traits:2753:15: note: in instantiation of template class 'std::__1::__check_complete<world_buildin
private __check_complete<_T0, _Tp...>
^
/usr/include/c++/v1/type_traits:2919:15: note: in instantiation of template class 'std::__1::__check_complete<std::__1::fun
world_building_gun, tile_bounding_box>' requested here
: private __check_complete<_Fp, _Args...>
^
/usr/include/c++/v1/type_traits:2930:11: note: in instantiation of template class 'std::__1::__invokable_imp<std::__1::func
world_building_gun, tile_bounding_box>' requested here
__invokable_imp<_Fp, _Args...>::value>
^
/usr/include/c++/v1/functional:1115:33: note: in instantiation of template class 'std::__1::__invokable<std::__1::function<
world_building_gun, tile_bounding_box>' requested here
template <class _Fp, bool = __invokable<_Fp&, _ArgTypes...>::value>
^
/usr/include/c++/v1/functional:1141:35: note: in instantiation of default argument for '__callable<std::__1::function<void (world_building_gun, tile_bounding_box)> >' required here
typename enable_if<__callable<_Fp>::value>::type* = 0);
^~~~~~~~~~~~~~~
/usr/include/c++/v1/functional:1140:7: note: while substituting deduced template arguments into function template 'function' [with _Fp = std::__1::function<void
(world_building_gun, tile_bounding_box)>]
function(_Fp,
^
foo.cpp:4:7: note: forward declaration of 'world_building_gun'
class world_building_gun;
^
In file included from foo.cpp:2:
In file included from /usr/include/c++/v1/functional:462:
/usr/include/c++/v1/type_traits:2766:19: error: invalid application of 'sizeof' to an incomplete type 'tile_bounding_box'
static_assert(sizeof(_Tp) > 0, "Type must be complete.");
^~~~~~~~~~~
/usr/include/c++/v1/type_traits:2753:15: note: in instantiation of template class 'std::__1::__check_complete<tile_bounding_box>' requested here
private __check_complete<_T0, _Tp...>
^
/usr/include/c++/v1/type_traits:2753:15: note: in instantiation of template class 'std::__1::__check_complete<world_building_gun, tile_bounding_box>' requested here
private __check_complete<_T0, _Tp...>
^
/usr/include/c++/v1/type_traits:2919:15: note: in instantiation of template class 'std::__1::__check_complete<std::__1::function<void (world_building_gun, tile_bounding_box)> &,
world_building_gun, tile_bounding_box>' requested here
: private __check_complete<_Fp, _Args...>
^
/usr/include/c++/v1/type_traits:2930:11: note: in instantiation of template class 'std::__1::__invokable_imp<std::__1::function<void (world_building_gun, tile_bounding_box)> &,
world_building_gun, tile_bounding_box>' requested here
__invokable_imp<_Fp, _Args...>::value>
^
/usr/include/c++/v1/functional:1115:33: note: in instantiation of template class 'std::__1::__invokable<std::__1::function<void (world_building_gun, tile_bounding_box)> &,
world_building_gun, tile_bounding_box>' requested here
template <class _Fp, bool = __invokable<_Fp&, _ArgTypes...>::value>
^
/usr/include/c++/v1/functional:1141:35: note: in instantiation of default argument for '__callable<std::__1::function<void (world_building_gun, tile_bounding_box)> >' required here
typename enable_if<__callable<_Fp>::value>::type* = 0);
^~~~~~~~~~~~~~~
/usr/include/c++/v1/functional:1140:7: note: while substituting deduced template arguments into function template 'function' [with _Fp = std::__1::function<void
(world_building_gun, tile_bounding_box)>]
function(_Fp,
^
foo.cpp:5:7: note: forward declaration of 'tile_bounding_box'
class tile_bounding_box;
^
2 errors generated.
Clang + libc ++ wird erfolgreich kompiliert, wenn ich die Zeile "worldgen_function_t w (v);" lösche. oder wenn ich die klassen komplett mache typen.